How do you improve your erections?

I use a cock ring every time and mine-rock hard.

I fell asleep one night after alot of drinks and I woke up with a huge red penis. I noticed in the next few months my erection was a lot shorter and very curved to the left. I think I have lost 3 inches in the last year so a dude has to be careful falling asleep with one on but before I did I was rock hard and 7 inches.