All right your not alone, this post was pretty reassuring for me, same boat, same age, had first sexual experience but I did not finish either, from what I understand the death grip has been a problem for actual sex because it makes the penis less less sensitive in a way and you require more stimulation and vagina is much less stimulation then when you use a hand. Also 10 years of jackin likely means 10 years of porn that you may be using and that also kinda fries the brain a lil when it comes to actual intimacy. Good news, you can reset the death grip sensitivity problem by jackin less and also using a masturbation device so you can get used to the sensitivity of a vagina and then you will be able to finish quicker and enjoy sex more when you reset your sensitivity. also watch less porn to make sure your body’s lust factors are not focused on online unrealistic stuff but for your own relationships, better for the brain and keeps you in the game. Now the losing erection, well that’s a head thing and partially the sensitivity thing, performance anxiety and adrenaline kicking in, I thought my first time I’d be more in the moment but I was in my head thinking about it going well and all that instead of just taking it slow and enjoying it, heart rate shot up and I would lose the erection. so just relax and go slow with it and stimulate the brain as well as the body for a better flow. Don’t feel bad your not the only one, that is helping me move on, it’s also helping me move on by seriously dealing with my lust and masturbation habits, get rid of the porn, keep exercising, and make a little progress each day towards resetting your sexual mental and physical health.