I got laid a couple times but I'm still having problems getting hard

So I have had problems lately where when I have been with a girl I have trouble getting hard, and once I get to around 70% (just enough to be able to get at it) I blow my load after a few seconds.

Well I am already in the process of fixing the PE problem, but the last two nights I got laid I still had trouble getting it up. I know this is purely psychological, and I am only 19 years old, but its starting to get on my nerves. I wake up every morning with a raging hard on, and have no trouble getting one when I masterbate. I have no problem getting one when I’m making out with a girl, but once I start to get ready to have sex it just dissapears. What to do? The only idea I have now is to not be so tense and relax, but I dont think I’m all that stressed out anyway.

You probably just have performance anxiety, common when guys start to have sex with a new partner. As you become easy with each other and you gain confidence, the 100 percenters will be there for you.