I'm losing my man because of my inability to Release during Sex

"I and my man have been dating for some time now. We have great sex but the problem now is that I can't have an orgasm. He is not happy with it and sent me a message saying ''how can I be with a woman I can't satisfy?''. Please what can I do? Even when I try to pretend to cum he notices. I am so weak and worried. And yes I was circumcised. I need advice please I don't want to lose my man