How should I take care of myself in regards to my constan...

It's so good that you have the desire to work out! I'm usually too tired for it. You can do just ten minutes a day, it's more than nothing and it wont fatigue you as much.

I've noticed that when I kept pushing myself to continue exercising and kept going into PEM, my baseline energy levels got lower and lower and lower. It's best to stay on the conservative side when it comes to your activity levels, and your body will thank you for it!

I'd start journaling to get an idea of what activity levels you can manage without going into PEM. It would be best to back off from all exercise for a week or so and see if you improve. And then slowly add more exercise