So last night, me and my girlfriend fucked for the first time in like two weeks, In started with the usual foreplay (fingering, licking out etc) made her orgasm a few times before i decided to fuck her, just in case i couldn't last the distance.
so after about 10-15 mins we get into it, so i start of slow, getting used to the sensation, everything is going good, i fucked her for about 5 mins giving her a few orgasms along the way.
she seemed pleased so i thought i would give her one more and finish off, but your brain is a stupid thing it does things you don't want to happen and doesn't do things you want to happen, so I'm thinking about coming, nothing, i keep going, at this point she is moaning hard and scratching the fuck out of my back, i still have the scratch marks. So I'm fucking her for about 15-20mins, i slow down because she gives a little whimper, she says that it's "Kinda Hurting" so...I stop

anyway, i pester her for the rest of the night, hoping she gets back in the mood so i can finish off, she doesn't
Tl;dr: Fucked Girlfriend for 20mins, pretty hard, making her orgasm, she seemed to enjoy it, but said it hurt, so i had to stop.
SO my question is, should i feel like a failure for not coming, and hurting her, i feel like all she will remember from it will be me fucking her too hard and hurting her, and not the pleasure

I would like to get some answers from girls who have been in this situation.
Thanks, Snowblind.