don't need sympathy?

This post is going to be deleted soon. I don't need your sympathy or hate. Just need suggestions. Please help. I'm scared for my dad and will do something crazy if anything happens to him. My mom has been cheating on him for years. She thinks its love but it has been a few guys over the years. I never told my dad because I didn't want to break his heart but recently because of some reason it all came out and I told him. Now they are still together, my father asked her to leave the guy and it will be ok. She refuses and says they are just working together but she is a big LIAR and has always been because this is not the first time. None of us are ok with it but we can't stop her and they won't get divorced because of many reasons including the children's lives. Yesterday I was talking to him (I live abroad so he's basically alone because mom goes off for "work") and he just said something that shook me and scared me for his well being. He said insaan ghut ghut k jeeta hai. mujhse dekha nhi jaata. this and that. and i died inside. I thought i would actually unalive that shithole guy who refuses to push away my mom saying she goes to him and he doesn't ask her to come. Tell me what to do. I need ideas on how to solve this. i will fucking burn everything but i feel so helpless right now because how do i do anything? what do i do? Please help