Too fucking nervous for having sex

After 6 years lately I'm in a growing relationship with a woman (even she lives far away from me). I met her on vacation and we got along very well with each other. We would fit perfect to each other, I guessed. And I feel attracted to her (and she to me), so we've met two weeks ago. But there is one thing, that happened to every girl I had before: my nervousness when the show is starting. My errection stopped immediately and I have no chance to get errected in this moment. I felt miserable everytime, when this happened.
But I gave her oralsex, as apologize (I don't feel disgusted by doing it btw., I have no problem with that).

What should I do? I thought about taking a break with fap for 2 weeks, so that it will better work.
Maybe my nervousness is connected with my virginity - I never had sex in my life and don't know how to handle this. Should I tell her, that I'm a virgin? I didn't make indications of being virgin to her.

 

I told her, that I got fucking nervous. And thanks god she shows patience and understanding to me, compared to the girls before her.

 

I could do nofap for a half year, but I didn't have a girlfriend during this time.

I fear about doing it wrong, ashamed, don't know how to do it right.

Well there are moments where I get errected, this happens when I'm relaxed. But when I try to do it I lost it.