What should I do about a sexual assault I recently fell victim to?

I was assaulted at, what I thought, was a safe place last week. I am a man, and, well, it was the first time I got a blowjob from a man, and, it was my first time sober, and, well, he would not stop when I asked him to, even when I grabbed his head and said no, but he did eventually stop. I went home and cried, because I thought I had asked for it. I didn't think I could tell the authorities because I am a drug addict, and I didn't want to get in trouble. Plus I did give consent at first, but, then I changed my mind, but he didn't stop. I really don't know what to do. I am feeling overwhelmed with emotions and depressed.