When should I tell him I'm genophobic

I haven’t dated much in the past 5 years due to bad experience with guy met online. Now I’m finally ready to date but am in recovery from mental health issues, not working or in education and pretty much isolated friend wise. But my biggest problem is I’m genophobic, something that has got worse past few years. My question is after a few dates, guys tend to ghost me or dump me if something sexual doesn’t happen. I avoid sex for as long as possible which is usually 4 or 5 dates. This is a very personal problem and not something I’d want to disclose to just any guy. So when should I address this when I start seeing a guy that has relationship potential, or how do I address this? I’m mid 30s and never had sex. A guy is gonna run a mile when he knows this, right. I think I’m finally near a place where with the right person I could conquer the fear but advice needed!