Can't Orgasm 🤦‍♀️

So I've had sex a few times and they all felt really good imo. I always have the urge to pee and ik that's the feeling of orgasm based on what he tells me but I can't seem to let it out.

I feel so bad because only my fwb finishes and I don't. Pretty stressed about it sometimes because I want to know how it feels like. Idk if it's because idk my body well enough too :/

Need advice pls, thanks.