I don't think this has anything to do with maturity. To imply such is adding further hurt on top of what Artchic is already experiencing.

Artchic, I see this as you being in a very vulnerable place, especially where rejection and validation are concerned. You'll need to be very careful about protecting yourself from such situations because people are a$$holes that generally lack empathy and have no compunctions about hurting another person. You must only show vulnerability to those who have properly earned your trust. Even then, you must be prepared to revoke that trust if the other person shows they are unworthy of it after all. Strangers cannot be trusted at all.