A Poll For Women: How Hard Is Hard Enough

I am dating a guy (we are late 30's), and even though when we first started dating we had sex every night after our first hook up for six weeks. Sometime is was multiple times a night. But problem is, my bf has a hard time staying hard, and I really only enjoy sex when my man is super hard. I love the feeling when he cums, cause ten I feel him really hard. But a lot if the time, he is kind of soft. I would guess 5 out of 10 soft. And he doesnt last long either. He has some back/neck injuries that prevent him from excersice. He was trying really hard to improve his fitness, but he wound up hurting his back and had to stop running. I am really losing interest in him cause of his problem, but I really love him. He has seen drs and specialistest like 4-5 times now and is trying so hard to be a better lover, but his body and his sex ability just aren't able to get me off like I am used to. He treats me so good, and he loves oral and can get me off that way, but I really need hard sex and without it i am losing interest.
He has tried a couple pills, and they help a little, maybe get him to 8 or 9 out of ten, but he still doesnt last long.

how hard is your man for you to enjoy sex ? Have you been able to enjoy sex and a relationship with a guy who can't make you cum from sex when many other men have done it so easily ?