Why can't I cum ? ☹️

I hate sex now . I don't really care if I cum or not 🤷🏻‍♀️ but she does, and it makes her feel like shit. I'd feel like shit too, I helped a girl come out the closet BUT I CANT EVEN MAKE HER CUM ??! Wow ... She can tell if I fake it so there's no need for that 🙄 and when we are doing "it" , it's not to say it doesn't feel good.. it just like jack in the box. I have fun getting cranked up but I never go "pop goes the weasel".. I've never came with anyone else either 🙁 and it's just sooo frustrating. Where did I go wrong ?