I relate to alot of your feelings. Im 53 though. I have given in to my feelings most of my life and allowed myself to full fill the diagnosis. I suggest you try to avoid that fate.

I am not a therapist. So this is just an opinion. Your depression is to a large extent just a symptom of your avoidance and fear. It will of course get worse as you give into it. The alternative is a huge challenge. To get over the depression by taking action that in turn brings up the fear and anxiety.

My only suggestion for someone so young with so much to look forward to, if you can overcome, is try to find a passion of some kind that does not require you to confront your fears all the time. Throw yourself into it 100%.
Write
Paint,draw, create art.
fix things
decide to have the best abs in your neighborhood.

find things to do alone that after a long while will add value to your life. Things that dont require you to challenge your fears so much. Then you might find that pride in your devotion gives you more courage .

Good Luck, Do as I say not as I do, lol.