orgasms.. help

Me and my boyfriend have been together for a while now and he's great and I feel like he knows what he's doing but I never ever orgasm or enjoy sex that much. We have tried everything and just nothing. He feels bad about it sometimes and always tells me I have to focus on cumming but how can I focus on it when I don't even know what it feels like? I'm scared its never ever going to happen to me. I don't know what to do 😩