If you have to do this, then you either have a health issue for which you see a doctor, are physically impaired, have an issue with trauma that prevents the act from finishing, or you lack desire for the partner you are with.
Instead of focusing on faking it until you make it, take care of your partner and then talk with them.
Creating seven excuses to not be an adult or to be a biological male instead of a man is not a great thing.
Is it easy to do? Fuck no.
I have experience in this area. If your partner shames you, then realize that this person is immature, childish, and probably not a person you should have long term intimacy plans with.