I struggled with depression toward the end of my high school career. My best friends from growing up had found others and essentially deserted me and I was very lonely. My social life was essentially non-existent.
Everything changed as my next step came and I started new. It really is a clean slate once you graduate and I developed a completely new social circle relocating to college. Think of the end of high school as a new start, because it really is.
Also, don't be afraid to reach out to a professional. I saw a professional just once and that was the beginning of feeling better because I had never really had the opportunity to just spill everything to someone. Even if you don't go the professional route, opening up here is good and if there is someone else that you might be interested in opening up to about this, a parent, grandparent, sibling, community member, educator, etc., I recommend it.
Feel better