My boyfriend has no erection

Hello! Advise how can I be?
To me 24. We meet with a guy and like each other very much. He loves me. It's up to sex and here on happened that his penis becomes sluggish somehow. It's not hard as the iron. and so a couple of three times. He applied to the doctor, passed all the tests. ABSOLUTELY HEALTH. The doctor advised him to look for the cause in the head. As it turned out he was just afraid of not satisfying me and disappointing me.

I said that there is nothing terrible in this and everything will be ok. Now he is more confident in himself (it seems to me), but there is one POINT. His dick does not stay hard as it should be generally ... It seems to be standing, but soft as a piece of the meet.
It is strange, but even when I make blowjobs for him, does not help. And petting. And caresses and massages ... still listless and soft. I already despair a bit, I think probably reason could be in mine attitude? I just get a little pleasure from sex (I can say I do not get it at all), but I do not want to leave my guy.
And about the second time even generally keep quiet .. in the process, it can simply fall down and will not hard and rise anymore.
Thanks in advance for answers.