slc_melissa

Can you list out a few meals worth of foods?  Although some energy loss at the early stages seems normal, it sounds like yours is more extreme.  I'm wondering if you may not be eating enough.  It's really easy to accidentally go low carb. It's also easy to not eat enough fat to cover the accidental calorie gap.
Are you eating any sweet potatoes / potatoes / butternut squash kind of starch?  If not, I'd add those to 1-3 meals per day.  (Also, depending on female/male and where one is in the cycle, more starchy carbs can help.)
I agree with prepping meals, I don't get food boredom, so I like to make big batches of things (say, crockpot full of chili) that feeds me for 5+ meals.  And meals can be really basic and totally not instagram-worthy.  3 hard boiled eggs, a handful of olives, and a sweet potato I cooked in the microwave....takes minutes, covers all the bases.  Frozen veggies heated up with coconut milk and a can of salmon or chicken and few spices - super easy and I didn't even have to bust out a knife.

I like to have go-to meals that I call pantry meals - meals that take minutes and are made up of stuff I'm likely to have in my freezer/pantry.  It's important to remember that not every meal has to be a big production.  In fact, none of them do.  You don't have to follow recipes, or buy any specialty items if you don't want to.  Your meals can be the most boring, least picture-worthy-on-instagram as you want.
Examples of pantry meals:
Super easy coconut soup:  Bag of Frozen vegetables, can of coconut milk, can of salmon or chicken.  Heat.  Add salt and pepper.  Add curry spice if you want.
Or: Can of chicken or tuna, can of diced tomatoes, add some olives.
To minimize dishes, I also like to make sheet pan meals.  With two racks in the oven, for instance, I'll do meatballs on one rack, and roasted vegetables on the other.  
To maximize time, after doing the two trays above, I'll put another two trays in the oven while I'm eating dinner from the first two trays, and have leftovers available.

No, re-creating baked goods is out:
Do not consume baked goods, junk foods, or treats with “approved” ingredients.Recreating or buying sweets, treats, and foods-with-no-brakes (even if the ingredients are technically compliant) is totally missing the point of the Whole30, and will compromise your life-changing results. These are the same foods that got you into health-trouble in the first place—and a pancake is still a pancake, even if it’s made with coconut flour.

I think Settyfitness was asking about how many days per week you're working out and how much time you want to put into the gym....if you're doing 4-6 days, no problem with doing split body routines.  If you're talking more like 2-3 times per week, your time might be better spent with a full body routine.

If you haven't been having migraines and then suddenly are and think it's food related, the real test would be to compare what you just ate to what you've been eating before.  Is there anything that you ate recently that you haven't been eating?  Or ate a lot more of?
But to answer your questions:
Yes, it could be a stress headache and from not sleeping well.
Yes, it could be there is a compliant food that doesn't do well with you personally.  For instance, the amount of nuts and almond milk you listed would destroy me.
If you're really dragging all the time, it could be food related.  I personally do better with more starchy vegetables than you've listed.  I especially make an effort to eat a lot of (specifically cooked) vegetables at breakfast, it really sets my day up well and has an effect on afternoon energy.

I feel like the almond industry has done a stellar job somehow advertising themselves as "high" in protein.  Yeah, they've got some protein, but they are much higher in fat and are considered a fat source on the whole30.
The unflavored paleo protein from Amy Myers has no sweeteners or other ingredients:  https://store.amymyersmd.com/products/the-myers-way-paleo-protein-unflavored
I'd say it needs to be blended.  (You can't just stir it into something, in my limited experience.)
Maybe a blend of pureed sweet potato (you can find cans of this in some stores), coconut milk, and protein powder?  A little bit of fruit for flavor if needed?  (A more complex carb like sweet potato might do your body better than the fructose in fruit.)
Nice job on staying compliant most of the time!  Sounds like your're rocking it.

Well, if you're post Whole-30, you can do whatever you want smoothie-wise.  The bigger thing that stands out to be is that you have no protein in there.
There seems to be two different recommendations on the website.  From the meal planner pdf: https://whole30.com/downloads/whole30-meal-planning.pdf
They recommend Protein and Fat prior to a workout.  (I'd say this is especially for like weight lifting type workouts.)
There is also this article, which seems to be more geared towards long effort/high intensity type stuff (if the workout is more than 60 minutes at a continuous moderate to high intensity): https://whole30.com/whole30-pre-workout-post-workout/
They recommend Protein and some carbohydrates pre-workout.
I think it's worth playing around with to find out what works best for you with what type of workout, but add some protein to it in either case.

Pretty sure the "peach nectar" rules it out.  Although not specifically called out in the sneaky sugar download, https://whole30.com/downloads/whole30-sugar.pdf, it certainly falls in the same realm as other nectars or monk fruit extract.  In my opinion this product is best saved until after a Whole30.

I'm not saying there is anything else in the nectar, I'm saying that nectar, being a concentrated thing to make something sweet, falls outside of how I would interpret the Whole30 guidelines: "Do not consume added sugar, real or artificial." is the first thing on the "No" list here:
https://whole30.com/downloads/official-whole30-program-rules.pdf
Fruit juice is allowed, but even then it's not recommended to drink it:
Fruit Juice: Yes
Fruit juice is the only acceptable added sweetener on the Whole30. (We had to draw the line somewhere.) Use it to flavor sauces, soups, or entrees.
Tip: While drinking a glass of fruit juice is technically compliant, we really wouldn’t recommend it, even if you juice it yourself. Juicing strips many of the nutrients out of the fruit, but still leaves all of the sugar. We’d much rather you just eat the fruit.
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Yes, I get that this is not a glass of fruit juice, and it's often recommended on the forum to add a small splash of fruit juice to water when people are looking to liven plain water up, but even if you make the argument that peach nectar is a form of fruit juice and technically compliant, I'd still stand by leaving it out of a Whole30.  It's also possible nectar means different things in different places.

If you're eating nuts as your primary protein source, I think you'll be lacking a lot of protein. Nuts can be very hard on the digestive system, are recommended as a handful every other day at most, and don't have great omega 3/ omega 6 ratios. Anecdotally, nuts have been a factor in a lot of people's skin problems on the forum.

Please note that sugar free doesn't necessarily mean it's whole30 friendly, you still need to look at all the ingredients.

I like this soup for breakfast:
http://scooterandtrianglegirl.blogspot.com/2011/03/sweet-potato-kale-and-sausage-soup-this.html
If you're using pre-cooked sausage like I did, watch the ingredient list.  This made a really big batch.