It’s understandable to not want a doctor poking around. I think a doctor probably could help, but since that’s not preferable, I’d recommend doing some self research, maybe on Vaginismus! Physical therapy or talk therapy may also help in the long run.
You could continue experimenting (with lots of lube!) or just focus on other sexy stuff that doesn’t involve penetration. You could try experimenting alone as well, as your body might feel safest that way.