Getting ready for sex

For Christmas break I went to the east coast to visit family and I hooked up with one of my friends there and it was really hard to have sex. (I’m 17 btw) Not only was he big but I’ve only had sex one other time and I’m still really tight. I’ve tried doing things to help my situation like masterbating but I’m just not into that so I’m not turned on and it doesn’t feel good and I don’t know what to do :/