I really need some support

So... My stepdad has been getting really affectionate lately. I just turned 18 back in December and it's like he's been looking at me differently. Well, I graduated last month, Class of 2016. I had a huge party on Memorial Day with swimming and dancing and all kinds of stuff. The day after I was super duper tired and I was half asleep...and my stepdad came in and laid down with me and started rubbing my back. I felt seriously uncomfortable but I didn't really know what to do cause everything was really hazy and I can't remember all of it. We ended up having sex... But I didn't really want to. But my body responded and I got turned on and I feel so disgusting about myself. I told him it should never happen again and it hasn't but he won't stop being affectionate and touching or hugging me. I want to vomit every time he touches me. I don't have anyone to talk to about how it makes me feel and I really need some help. I'm just biding my time here until I move out to Stephenville in August for college but I have nobody.