I can’t finish!

I have never been able to orgasm with another person before. I can make myself finish easily, and the few times I have finished with another person (and I mean few. Like 3) it’s only been because I was touching myself. I have faked waaayyy too many orgasms and I promised myself that I’m not doing that anymore. But I’ve started talking to a guy that I like recently (we won’t be physical at all for a while) and I’m so nervous how to bring this up to him. I’ve mentioned things like “I take a while to finish” or that I have a hard time with it and get in my head, but haven’t told him that no one has ever been able to make me finish. I just don’t know how to go about this in a way that doesn’t make him think or feel that it’s his fault or that he isn’t doing something right. How do I address this??