My T has asked me a couple of times if 'anything' ever happened to me. I'm pretty sure it didn't but I can never be 100% either. The things you mention could just be as a result of careless parenting - like you knew about sex because your parents weren't discreet when you were little and early/frequent masturbation is a form of self soothing (I used to do this too - still do really if I'm honest...). Or something *could* have happened - it's impossible to tell. I say if it's bothering you you need to discuss it with your T regardless.