Fiance is leaving me I'm 17 weeks pregnant

I dont even know where to start. We were the perfect couple we are engaged and planned our baby the only problem we had is my ex interfering since i have a daughter with him. My Fiance cant let it go that stuff happened in the past i never have cheated on him or anything like that I hated my ex long before i even met my fiance, however for my daughters sake there was still a few photos in the house and i still had him on Facebook as we messaged through there about when he was picking my daughter up etc. My fiance and I have argued about this in the past and got over it way before trying for our baby. Also my ex has text my fiance things like saying I was asking to get back with him just before me and my fiance met etc which is 100% not true but is obviously in my fiance's head. I have never given him any reason not to trust me and have been honest about everything from day 1. I no longer have contact with my ex everything goes through my parents in regards to picking/dropping her etc and it's been that way for around 6 months. Nothing at all recently has happened but suddenly 4 days ago he doesnt want to be with me anymore. He says he still loves me but cant get my ex out of his head. We recently found out our baby is a girl and he wasnt happy because i had a girl with my ex and it will be 'the same'. I really cant deal with this at the minute i love him more than anything i cant see a future without him in it and i thought he felt the same or i would of never planned this baby. I don't even know what i am asking i just need some advice. I cant deal with the thought of him with anyone else it is killing me he is now single and might sleep with/kiss someone else. He isn't texting me to see how i am or anything and i really dont know what to do. I have stayed at my parents since this happened, he says he is moving out tomorrow. I want to go home tonight and try and sort this but how can I if he doesnt want me 😭