33 weeks pregnant and found my bf cheating

Today i found my bf cheating on me with another girl.,the girl texted me on fb messenger that they are seeing each other like 3-4 months ago.,i am devasted and dont know what to do,it sounds pathetic but i ask the gurl to leave us alone as i wanted my son to have a father.,im in the state of my emotion that i even beg for it to leave us alne.,the gurl forwarded the message to my bf and he got soo soo mad at me and telling me im lunatic. Instead of going to my side and say sorry he said he cant deal with me anymore and the baby thing stress him a lot so he said he is going to the new girl instead,and just leave me like that-im broken and dont know what to do😭😩