feeling confused

okay so ladies I feel so confused my fiance and I been trying for a second child together we have a son together he has two older kids to his ex who passed away of cancer and I have one from a previous relationship, all my fiance and I been doing is fighting arguing, he says I'm crazy I need help and that I'm seeing things he got mad and made another facebook he passed out and I seen all these messages to other females but he swears up and down I'm the only one he wants to be with we been in this relationship for three years this month on the 27the... ugh its bad enough I came down to my grandmothers house to give us space from each other...