Hi AnxiousGirl, I deeply sympathize. I, too have great fear of medical professionals.
It's very possible the stress and the weight loss have combined to affect your period. I've missed multiple months before or had extended bleeding during times of great stress. Can you try and take good care of yourself, remember to eat well and drink water, and do something that relaxes you? I'm willing to bet that that will help.
You're going to be okay. This happens to a LOT of people and doesn't necessarily require medical intervention. I'm not a doctor, but it's really only going to be problem if you start having unusual pain, fever, or other physical symptoms. I would suggest that you need to drink plenty of water and eat foods with plenty of iron in them, so you don't become anemic or dehydrated.
Have you considered that the intensity of how you're feeling, and what you're experiencing with your period, may be because your hormones are out of whack? Often birth control pills can get that under control. Yes, that takes a trip to the doctor and a pelvic exam, so maybe that's something you can consider and talk to your therapist about preparing for if you want to try it. But you could also try and manage it through diet, relaxation techniques, and all that good stuff. My periods got way more regular when I was going to the gym frequently.
Might I suggest you prepare yourself to talk to your therapist about it, since you're having a hard time with it? Our society teaches us to be ashamed of our periods, even though they're natural and nothing to be concerned about. You're far from alone in dealing with embarrassment over it. Try watching some youtube videos where people discuss periods, google for and read some stories about empowerment and normalizing periods as a part of life, listen to people talk openly about it. Seeing others talk freely about it and not be embarrassed might help you normalize it as well.
You are in school, you are working hard, and that is not wasting your life. You're in therapy, working to learn to deal with your anxiety, and that is not wasting your life. I'm sorry that you've had to deal with such stress and anxiety, but you have made it this far, and that means there is something in you - grit, determination, strength, courage, passion, hope – that has carried you through. That is still with you, and even though you struggle with being afraid, there are still good things in life worth having and enjoying. Try to celebrate them, and yourself, and your victories.
You can make it through this. I believe in you.