Difficulty achieving orgasm for both of us

I recently made a new friend and we hook up pretty regularly. We are in high school so sadly no sex yet, but last night I fingered her, she gave me head, then I ate her pussy. We are both semi-experienced in this field yet neither of us could cum. I could blame this on several factors, i.e. we were in the back of a minivan, I was fucked up on multiple substances, we couldn't play music, etc. I think the reason was because her blowjob was extremely toothy and she said I was hurting her with just two fingers. Can somebody give me some tips to make this a painless and more comfortable experience?