Me and my girlfriend are ready to have sex, but for some reason every time I put the condom on I cannot stay hard enough. We have been together for over a year and are perfectly comfortable and willing. What can I do?

My girlfriend and I have been going out for about 5 months now and this is my first time having sex with a girl that Im madly in love with. I never had any sexual problems prior to her, but they were girls that were just friends and we both agreed to have no strings attached. Every time we have vaginal entry it never seems to go right and she ends up being sore and uncomfortable. I try to comfort her and ask what I can do to make her more relaxed and comfortable and what may feel better for her. I care a lot about her pleasure and I want to turn our sex from a 1 to a 10. My erections come and go especially when we run into complications and when she starts feeling great pleasure I end up cuming to fast, is there anything wrong with me? She is the only girl that Ive been with who can make me precum more than once and makes me cum fast. I get really embaressed and down when this happens in front of her and I want to know what I can do to help myself and what I can do to make vaginal entry really enjoyable for her. She does enjoy vaginal entry but has never had an orgasm from it with me or other guys. I have given her many orgasms from other types of sex but vaginal entry seems to be a big problem. Is there anything wrong with me having a problem with getting an erection sometimes im 21 years old and it bothers me that this happens. She just seems very hard to please and I want to be the best for her like I was for other girls.

I have a question about ED. I think this is fairly rare around my age (20), and I was wondering if it's generally a physical cause or a psychological one? It's happened 3 times in my life, but even so it tends to bother me. The last time I had a stomach problem at the same time, could this be related? Also, do you recommend the use of anti depressants to solve this problem?

When my penis gets hard it bends to the left so like my head points left instead of straight: is this normal? If it is not can I fix it? If i can fix it how?

Is it bad for a guy to have an erection for an hour or two? What does an erection feel like for them?