Sorry to hear you don't have a school psychologist. That would have been my suggestion as well. Still, a guidance counselor who is any good will see your depression well worth their time. Please don't sell yourself short in the presence of seniors trying to get into college. You are trying to protect your future as well, right?

Are you in a small town? That can make sharing struggles harder sometimes, but it's still important to find someone you can trust. Your history teacher might be a good resource but know that there are some things teachers are required to share with administration/family. Any self-harm or intent to harm, for example. A middle school history teacher was a huge help to me as my depression emerged but she also had to report it when I shared that a friend of mine was suicidal (nearly ruined that friendship when the parents got involved). Later teachers provided a lot of support when I didn't have others to go to and my mom didn't seem like a safe person.

From the vantage point of my late 20s, I can say that while my mom still doesn't get me entirely, she's come a long way in trying to support me. Don't give up on your parents entirely. They may surprise you down the road, even if it seems impossible now.