I'd say chastity is a good way.
Hormones pills could help too.
I heard you could break your dick too, when you get hard, you push your clit between your legs the farthest until it hurts and goes limp, then you get hard and do it again and again and again for days and weeks, until you can't get hard again. Idk if it works, never tried, but maybe you can search that path.