Sex during Ramadan

This is gonna be a short one.

I’m a revert me and my girl friend took shahada 3 months apart and we’ve been Muslim for 8 months.

We never got married in Islam. We’ve going through ruff patches in the relationship. Honestly because of me and my lust issues.

But me and her have been having sex off and on during Ramadan. I feel like my whole Ramadan is down the drain fr. Like I get Allah is all merciful and all that but I really feel like I just threw my first Ramadan ever down the drain cause of my lust and cravings for sexual and physical desires. Yes I know keep fasting, keep praying, keep repenting. But why do it all if I can’t change. I feel like I’m playing wit God if I do all those things and still fall short.

And do I fast 60 days for everyday of sex during Ramadan?

Edit: we’ve been living together for 2 years