Got so much regret now

So I stay in a 3 bedroom house and my gf decided to rent the two other rooms to her friends both dont work so i dont even realy charge them, i pay for food and all of the expenses while my gf of 2 years pays part of the bond for the house. 

My gf cheated on me a year ago but we got back together and mended our relationship. So 2 months ago my gf decideds that she is going to spend a week at her grans place so i was left alone with her two friends i honestly wasnt that close with them or anythink was just a hi how u kind of thing. 

So anyway the night my gf leaves her friends ask if we could all go out and grab pizza and a little alchol so i agreed, when we got home we decided to chill play some music and see can dance the best, this is where it all went wrong things started to get sexual, the twirking and all before i know it im watching two girls strip tease for me while i lay on the couch......I never thought i would cheat let alone on my gfs friends and two women with zero ambition, no brains, broke as fuck heck i even gave the one girl money to help her dad out. One thing led to another ended up having a threesome and after this i was hooked i had more sex in one week than i had in my entire life (i felt like it was justic for what my gf put me through) wats worse i never used a condom they both told me they were on the pill and stupid me i believed them.

So i continued to cheat even after my gf came back right untill 3 weeks ago when they both told me they were pregnant i was and still am shocked so i thought ok abortion but no they keeping the child and want me to pay them maintainace and unless i want my gf to find out i must pay them money this month to keep them quiet. What is fucked up is im only 24 + i put the house under my gfs name and now my whle life is basically fucked. I took them both to hospital ystrday and the doctor confirmed they pregnant, what makes it worse is i know it is my children because they dont go out or have bfs or anything. 

I was literally tricked into making them pregnant they knew i was earning alot and my parents are probably going to cut me off now once they find out, my gf going to take the house even though i paid more than she did towards the bond since its all under her name. Im going to be absoluty broke now.

Dont know what to Do. Even though i was tricked the law states i made an assumption that they were on the pill so cant even take them to court nothing looks like all i can do is pay mantainance out my ass.