NEED SOME ADVICE

You're going through a flatline phase. Trust the process. It's a difficult process, but the rewards will undoubtably be worth it. This phase will end if you stick to your nofap goals and you will love and embrace sex with your wife after without any worries. This is what porn does to us- takes the joy away from sex. We can't let it to that. We must win the battle. Stay strong brother

 

Hey there.

I think in general, you need to accept that there is something that you cannot control.
A lot of people, i would say MOST people are afraid of their first sexual performance, cause the media, porn and society are putting a lot of performance pressure on us.
While there are "techniques" to learn and to become better at, it shouldnt be just about that performance. If you want to have casual sex, it would be a different thing, but still there, i think people are making a sport out of what is a human expression of both lust and affection.
If you are getting married soon, i guess you know the person and she loves you. So maybe you are afraid that your spouse wont love you as you are. Or you want to appear very strong and without any flaws in front of her. This is more a direction of narcistic traits, or at least exaggerated expectations. No one is perfect. Plus she is probably nervous about it too.
People also have problems to get an erection because of being too nervous and not being able to relax and feel the lust. Or its porn-induced. So if its porn-induced, follow the guide lines of this forum to beat it. If you are nervous otherwise... maybe you can think about the worst case: you don't get an erection the first time. It is possible, but a lot of first times are very chaotic and not necessarily "good", whatever that means.
I wouldnt check by fapping if your dick works. If you are off for a while, your dick is gonna be back to normal eventually. I cannot say or promise it will be back for your wedding night. But if you continue to fap the chances are lower...
If she loves you, she will stay with you even if the first night wont be good.
And maybe you can talk to her about it. Do you think she will help you with that and accept it? I heard a lot of stories where women gave a lot of support and understanding...