Coping with back to school anxiety.

I'm going back to school the 10th, and I am very nervous. Not just generally, but specifically because of a very bad experience I had with a boy who was my friend, and then got a too close for comfort, which caused my anxiety to go nuts. I stopped talking to him, but the memories of what happened over a course of about a month, in which I allowed him to believe that I felt the same way about him, are still here. I was terrified of confrontation (as usual) so he forced me to do mild things that I did not feel comfortable with. But since he would randomly come over to my house without asking, I have an irrational fear of people ringing my doorbell. I hide out in my locked room whenever the doorbell rings, because of my anxiety. I do not know his schedule for school, so I am very afraid that he might have many classes with me. Also, we both play french horn in band, so we will be sitting very near or next to each other for about 45 minutes every day during my second period class. I have a lot of anxiety about this. Any advice?

Oh I know how you feel. I had those funny feelings in my stomach just reading your post. I remember this time of year when I was starting a new school year all too well for they were my worst...