How to get over the pain and anger of being cheated on by my wife.?

Ok here's my story last week my wife told me she only loved me as a friend for the past 3 to 4 years we have been together for 6 years.Then she got pregnant with our son and she and thats the only reason we got marred cause she was pregnant not out of love at all. Then a year later she got pregnant again with a girl she told me she tried to make it work in her head after the first one and even harder with the second one. We have been marred for a 1 1/2 and then she told me she has been cheating on me a month after we got marred with this prick at my work that i know. Then she hit me with a nuke she told me that the girl she just had most likely might not be mine. I just need some help on how to get over her it's just so hard to see someone you have been with for 6 years to be with someone else. It just make's me want to kill myself but I don't only cause of my kids even if the girl isn't mine I don't care I will still treat her like she is mine. So if there is anyone who can help me with some advice on how to get over this would be nice.