I'm so glad that you're feeling a bit better. It sounds like between your family, friends, and your self-relaxing strategies you have so much going for you when things get tough. It's a cliché, especially to hear from an older person, but it really, really does get better, especially after high school. Not only do you get more control of your life and get to meet new people and explore new things, but people your own age also become more mature and there just tends to be less of the behind-your-back drama.
I struggled for years with bullying, and eventually in high school threw myself into my studies, which was unhealthy in its own way. If I could go back and talk to my high school self now, I would say to worry less about getting good grades, and the people I didn't like, and just focus on having memorable experiences with my friends. Of course, when you're anxious at school, that's easier said than done.
But besides the wisdom that comes with distance from HS, we have to think practically about what can be done in the here and now. Have you ever thought about getting help for these anxious thoughts? Perhaps talking to your parents, a doctor, about setting up a mental health plan? I did this as a young person and I truly believe it is the single greatest reason for my current health and happiness.
What sorts of books do you like to read? What about movies or TV? Sometimes the best thing for tough times that you just have to get through (like HS) is to really get lost in our interests.