What do you do if you have trouble staying hard while topping?

One recurring problem I’ve faced is having trouble staying hard when it’s time to top. I’ve tried viagara with some success and some failure, but I’m also in my early 30s so don’t want that to be my go to solution and cause problems from using it at a young age.

There’s definitely been a couple times where I just wasn’t super attracted to the guy, but it has still happened in situations where I am very attracted to the guy and having a great time, but when it comes time to top, it goes away. I’ll be hard while we’re making out and during foreplay, and then by the time I lube us up, I’m soft again. It seems like when I have successfully topped, once I make it inside, I’m good to go for at least like 15-20 minutes lol but the challenge is getting to that point without going soft.

Am I doomed?? Any tips and tricks or general advice?

I don’t drink, do drugs, or use tobacco products any more, so it’s not related to any of those things either.