I didn't have a long-term relationship until I was 30. That ended rather amicably after two years. Immediately after that ended, one of my girl friends asked me out and we dated for a few weeks (she kept moving the goal posts but it probably lasted for a month). Then two things happened at the same time. First, my latent insecurity took over and I just couldn't relax. Second, she was probably dating her own student.
Now I'm discovering that I'll go on four or five dates with a girl, and that's when she either ghosts on me or gives me the "this is a really bad time for me" speech. I no longer mind being rejected because that's just life. But I HATE ghosting. What's so hard about growing some lady-balls and telling the guy she's not interested?
Anyways, just keep at it.