Ed Or Premature Ejaculation Or Am I Just Crazy

Hi,
i am 24 and I somehow managed not to have sex most of my life.
Ofcourse I watcha lot of porn and when I do I can get good erection.
But lately I been tryin to have sex with different women prostitutes(4 times in 6 mo) but I ejaculate very early (3), or sometimes I cant get erection at all (1).,
so first off is this normal?? (no not seeing prostitutes) erections?? If not
what xactly is my problem. Did I watch too much porn?? What is the difference between ed and pm.
Thanks.