mental health deteriorating

How do I fix my mental health? We can't afford a therapist, I've already seen one for my anxiety and it costs us a lot. 
I'm growing up, almost done with high school. I have no idea what I want to do with my life. 
I have one friend and she's moving for college. I'm going to be alone and I have no idea how to make new friends. 
I feel like dying all the time. I wish I didn't exist about 90% of the time. All of my feelings are built up and I can't talk to anyone about it. 
What can I do? 
Edit: 
Thank you for your help , guys. I'm currently in online school and I'm supposed to "drop out" and take my GED after I turn 18. I might be going to the local college for a vet tech program but I'm so confused about if that's what I want to do. 
I'm tired of school but I want a certain lifestyle I won't be able to achieve working without a degree or trade.  I'm just honestly so lost