How do you disclose your stutter to someone you’re dating?

How do you disclose your stutter to someone you’re dating? I’m talking to this guy I’ve met online but we also met in person couple of times ( not intentionally). It’s a long distance and we communicate via text, phone. But I try keeping our conversations via text. We’ve talked on the phone multiple times but I don’t like it. Obviously if it wasn’t for my stutter I’d prefer phone calls more. I can’t fully express myself or say what’s in my mind. Because of my stutter I’ve developed a phone phobia. This has caused us problems. We broke things off couple months ago because he thinks that I don’t share enough with him and reserved. The thing is he doesn’t know I have a stammering problem and I don’t know why but I’m having a really hard time telling him. This conversation makes me very uncomfortable. I know if I keep hiding it it will only make it worse. I’ve never talked about my stutter to anyone and it’s such an awkward conversation but I know it has to be done. I just don’t want anyone to pity me. Part of me is telling me to just end it if I can’t fully be honest. I don’t know what to do. Has anyone been in this situation? If so, how did you overcome it or solved it? My stutter is mild, I block more. The more comfortable I get around someone the more I stutter.