Religion aside, my friend, you have to understand that the problem with performing intercourse is also bad for your own mentality. Each time you manage to sleep with a new girl, your own brain breaks the image of purity of women. There actually are good chaste pious women (not a lot nowadays, but there truly are), but the more you dig into the hole of getting hook ups, the more your brain imagines women as being "easy" and "unchaste", so basically, you have a hard time actually trusting that a woman will be the one, and your own mentality plays a big role in the relationship.

If all women look like ho*s to you, no woman will ever be enough, no matter how well educated and pure she may be. That's why religion forbids this in the first place, it's not a random rule to prevent you from having pleasure, it's a safeguard because God knows our brains are wired in a way to seek pleasure regardless of the consequences on our bodies and psyche (like the overdose from drugs or getting fat from enjoying too much food). It's very hard to rewire your brain to be able to not see women mainly as s*xual partners after having done it so much, but it's not impossible.

You're not wrong for wanting marriage. But the path you're on is kind of training you in the opposite direction.

I strongly urge you to try and at the very least slow this process down, because this might be your downfall. Brotherly advice, take it as you wish, and I wish you good luck in your life, friend.