You can always try blue chew or some other med. I don't usually have issues getting it up but sometimes I just want to go for an extended sesh with a friend I haven't been with in a while and it keeps me hard and also prevents me from cumming so fast. Exercise might also help if you find yourself not as active as before.
It is very normal. Just from my own experience, I used to be the same way but it changed as I got older. Exercise can help and also just trying to prolong ejaculation. Make sure to have good communication with your partner as well about it.