Cheating

So about 3 weeks ago, I found out my Bf, father of my daughter cheated on me with a very young girl that I was super close with. I don't have a bunch of time to type the whole thing, plus I don't think anyone will make it through the lengthy detailed heart throbbing story.

Anyways, me and her were so close and it was completely shocking. He was or didn't seem that type of guy. We were together for 3 years, we just got our 1st place and I found out this happened about 8 months ago 2x. Not just once. I feel so betrayed and just need someone to talk to. I have no one to turn too and I am alone and lost in my thoughts. My heart is broken and my chest hurts, it's so painful. Idk if I am deciding to stay or leave. We have our daughter together and I have my son who thinks that's his biological father.

He says he's extremely sorry and learned his lesson. I can truly tell he feels horrible. I see it and he's never broken down like this before. I just don't know what to do. I'm lost in my thoughts and I need advice. From someone who can really help.

I dont know what to do. & some days I can't take it. It's on my mind 24/7 &I; I even picture it. I am a very visual person when it comes to everything and I keep it on repeat. It's really eating me from the inside out.

Please someone help me