Studying causing anxiety and burnout

Hello I'm new here and currently training to become a pediatric nurse but it's causing me anxiety and now what I think might be burnout. So far the studying has been a smooth process with very little stress but now I'm coming up to actually having to do mock exams and it's making me anxious. 

I'm OK with tests but having to go out to them in a large class is overwhelming to think about let alone actually do for real. I'm slightly disappointed as I thought I was over the worst of my anxiety and yet here it is like old times.

And then there's the burnout. It feels like autistic burnout but somehow worse than the first time I had it which I can't really afford to endure for the next year again. It will really destroy my studying and exams; and I can't let that happen to me. 

My burnout is exhaustion all the time, worse after doing something and I feel exhausted still even after a full night of sleep. This time it's causing me to struggle to remember things, so annoying, it's impacting my studying now and I don't know what to do about it. 

All this is adding to my stress making the anxiety worse and causing me to feel even more exhausted than before. I'm unsure what to do about this. It can't go on because it's ruining my life and I don't think the doctors will do anything as last time I had burnout they wouldn't do anything, just told me it was fatigue from anxiety and to take Sertraline and that made it even worse.

What helped you during burnout? 

If you have anything you think might help me please let me know. I'm desperate to get through this asap.