Losing my virginity tomorrow...

I know I am ready to do this with my boyfriend, and I am very excited but also very scared. We sort of tried to do it a couple days ago but got interrupted, and I was extremely tight when we tried to do it and it hurt very bad so we stopped before he went in all the way. I'm scared that tomorrow will be the same thing. I'm just scared it will hurt or I won't be able to open up for him or that I won't even like it. I know being stressed makes you tighter and such so I know I can't go in being scared. I'm not scared to do it, I'm just scared of me not being able to physically. Any advice on how to ensure I will?