I had a similar situation when I was about twenty. I had just broken up with my girlfriend of 3 years. I met a new lover (who is now my wife of SHIT! 28 years!). We got a bit wasted one night and started the ball rolling. But I was too wasted and I couldn't keep it up. So after several months of avoiding the situation, we found ourselves at a sleep over at a cabin with a bunch of other people. We hit the sleeping bag together in a room with a few others. As the nite progressed the fingers started walking and before long we were having a very quiet fuck while everyone else was asleep. That did it! Ever since, we have been doing pretty damn fine. So my advice is just to let it go and if things work out right you'll be perfectly fine. And don't let the size bug you. After all, lesbians do it all the time with tongues and fingers! Just got to hit the button.