How do I come clean to my SO after i lied to him for months?! HELP!

So my SO and I have had so many issues in the past year especially over my daughters dad. She is 6 and I do admit that my biggest mistake was not ever setting boundaries with him once I got into a serious relationship. I️ still tried to be his friend and “cordial” with him aftwr I got with my SO, just to keep things peaceful but it’s never been easy to coparent. There have been times where my ex has been inappropriate and I never confessed to my man about it, instead, I hid it and deleted texts and avoided my ex for a while until things felt friendly again. Nothinggggg has ever happened between us but I️ guess I just kept it from him for the sake of my daughter, to avoid fights and problems, because my man won’t waste time talking he’ll just go look for him. So, in April, my ex and I️ had a few long conversations about his current gf and their son and child support and custody, me as usual, not settling boundaries, listened to him vent. A few nights later me and my SO were going on a dinner date late at night it was about 10-11 pm and my ex called me around 11:30... it was a Tuesday. I answered because I had nothing to hide, but instead of it being a casual call for something important, my ex was like “what cha doinggg” and then I told him I was busy and that I was out with my man. Hw then said that he was leaving work and his car had broke down and needed a ride home. I was BAFFLED, Because though friendly, I NEVER speak to this man late at night and I NEVER would grant him a favor as such especially when my daughter was not with him. Immediately, my man took it the wrong way and said he was leaving and he had enough of my sneakiness. Stated that the only reason a grown man would be comfortable enough to call so late at night for such a favor, is because I gave him the authority and the power to do so with my actions. Which i agree with. I have never set the boundaries when he tried to push the limit, I would just ignore it, he asked me out for a drink once and i of course refused, but I never mentioned It to my man. My man has asked me so many times if I ever deleted texts and i continue to lie and say no, I recently lost my home Bcus since he moved out, I could no longer afford it and am now facing eviction at 9 months pregnant and he even questions the kid being his. He says that he has doubts because me and my ex were too friendly and too close at the precise time that we were breaking up and coincidentally, my ex and his gf had broken up in April as well after she took him to court for support and custody unexpectedly. I got pregnant in May and my bf says he just thinks it’s weird that we tried for over a year and then when all of this happens and me and my ex both end up single, I end up pregnant. Me and my SO were still sleeping together throughout April May June and July, I know I got pregnant in May but I️ definitely don’t doubt the paternity of my child Bcus there is never a way that this kid could be anyone’s since I haven’t slept with anyone else. A lot of my family judges his leaving Bcus they don’t know that yes, in fact, me and my ex were very friendly and that may have crossed the line between cordial and comforting and being that shoulder for him that I️ should have never been. I did delete texts but just because I was scared not because I was cheating. He has given me so many chances to tell him i deleted texts and if my ex was ever inappropriate or insinuating anything and I lie and tell him know. So last night, he finally told me I know u deleted texts because I saw you text your cousin about it and I️ know the things he said to you because, you told your cousin about I.t and then stupidly told her that you deleted those texts. Which is true, I’m afraid to be honest with him now Bcus I have lied since May and my baby is due in 4 weeks. He’s going to ask me what those texts said and y I deleted them and I don’t even remember those texts, and I don’t even know what to say at this point because I’ve been so scared to tell him. I don’t want him to think that I️ cheated or that I had reason to hide anything from him. He says he wants to be with me but he can’t respect someone who is lying to him over and over and now that I know he know Bcus he’s right about me texting my cousin about things, he says he can’t be with a woman he loves but cant trust. I don’t know what to do. I’m so scared and lost and I just want my baby back. He says he just wants to know I️ can be honest with him. How do i come clean without him losing his mind? At the same time I don’t want him to think he can talk down to me cus j lied to him for so long or continue to throw it in my face down the line of I do come clean, which he has the tendency to do. Everytime we argue he brings up all my last faults. Idk what to do I’m scared and lost.