Both me and my gf have failed

We have been together for about 16 months now, and we fell in our flesh, if y'all know what I mean...

Both of us are devout in our faith and love for God, but it just happened in the moment. I plead to God for forgiveness and we have prayed more than ever before, but I can't stop feeling such a heavy guilt as if I am beyond a failure...

What do I do? I can't marry yet, I'm not ready for anything like this. I tried, I swear I tried, I begged her not to, but then it just happened! I can't feel nothing but shame now anytime I see my Bible or attend Church. I'm beyond regretful