Here’s the good news: You’ll be out of high school in two months. You’ve been experiencing a form of bullying. In the age of texting, a mistake can get inflated bigtime and next thing you know, someone like yourself is on the outs with half the school. People are reluctant to side with you because they are afraid they’ll then be on the outs too. It’s not right. It’s not fair. But it happens. If it again escalates to more harassment by texting, you can go to the administration for help. That won’t win you friends but it should stop the bullying. Since the trash talk happened a year ago, though, there probably isn’t much you can do now. Hopefully, it won’t happen again. Hopefully, at least some of the people who picked on you will grow up in the next few years.
Meanwhile, you’re right. By senior year, everyone has their group and it’s very hard to get included. Fortunately, life isn’t like high school and high school doesn’t last forever. My best suggestion is that you just be pleasant to people and ride out the next 8 weeks. Meanwhile, start looking around for places where you can find new people who share your interests. Think about taking a class at a local community college this summer, finding a job that will help you find some direction for a career, or applying for a gap year program. I think you’ll find that new people will give you a new chance.
BTW: Very few people think of their high school years as the best years of their lives. For many, it’s the worst. Life starts for most people after high school graduation.
I wish you well.