Vent 😞💔

So... I am due December 19. It been about a week since I found my fiancé chatting with other girls and snapping them photos. I left for the night and went to my mother... when I did he went out and partied up with a “friend” and continued the chatting. I drove to his friends and made him leave in the morning and asked him what he wanted.. he said me. But this morning I went through his messages and he was talking to his buddy about how he didn’t know if he wanted me or not , or if it was the alcohol and coke messing with his head .... I didn’t even know he was on coke. He had a previous issue in life with it and almost died. Idk what to do.... my mind is going crazy and I have done so much to keep busy but have run out of things to clean and out together ... I am a stay at home mom and also have a 2 and 4 year old home. I’ve done everything I could to get him to stay away from the drinking and drugs but obviously it didn’t work... and now I feel like I just am not enough for him and maybe never was. I can’t stop pacing and idk what to do.