Can two faps in 82 days ruin all my progress?

I am on 84 days without looking at P, I can not say the same for M. I did M twice this week, and it very well might have ruined my relationship with my girlfriend. I gave into temptation twice this week and it ruined everything.

On Monday morning I awoke with a massive morning wood and did M for the first time in 77 days. While doing it, all I thought of was my girlfriend. Everything seemed normal, my day continued like normal. I had sex on Tuesday and it was actually better then normal, I lasted longer.

Wednesday I had the day off work and I was home alone, I did M again. This time I started thinking of my favorite P scenes / stars. After the deed, I felt alone, depressed, ashamed.

Friday I hung out with my girlfriend, we had sex. My erection was very weak, but somehow it was enough to penetrate. After she wanted go to a 2nd round, this is normal for us. During the foreplay I couldn't maintain an erection I didn't think much of it. The time came for sex, and my erection died completely, and it would not come back. She didn't seem to mind, said its okay you're probably just tired.

Saturday night were fooling around, everything seems okay. I have an erection, then the time comes for sex. I put the condom on and my erection begins to fade, and eventually completely gone and would not come back.

She cries, and thinks its her fault. I feel depressed, angry, and alone. Did fapping twice really do this? How could I come so far and lose everything