Relationship falling apart

It's a long story, We've been together for 3 yrs already and we have one son together and I'm currently pregnant with our daughter I'm 36 weeks

**(he has cheated and left before but came back and from my knowledge he hasn't done anything for a 1½now but that's what I know about)

I just found out some things that broke me and all I want to do is cry but I always run and hide when I want to cry so he cant see or hear me

A couple of nights ago we got into a argument and when I look at it now it was over something small I wasnt even mad but he kept pushing and pushing for a argument and the whole time I was asking him

"why are u trying to start a argument like I'm fine I'm not mad so why are u so upset "

After a while of hearing him complain about things he finally says this

"I'm sick of pretending I love you but I cant no more I dont want to be here"

Let me tell u my heart sunk i was like what i never expected to here that i thought everything was fine we always sit down and talk because I want us to have a good communication so we dont get confused where the other is coming form

So I started to tear up and say

"what do u mean I have been seating u down and talking to u about everything how we feel where were at hows work etc and u never ever told me u feel like but now out of nowhere u tell me this"

He stayed quiet and just said he cant

I took a long shower and sat and cried and when I got out I expected to see him leave since he had everything packed but no he was asleep with our son in his arms

And today I look at him and I can see hes not having it

I tried hugging him holding his hand but he just didn't want it he didn't hug me back and kept pulling away which break me hurts me cuz I'm like I love u I gave up everything for us and now out of nowhere u pull this stunt especially now when our baby girl is almost here

I'm just so confused like what happened we were fine we were prefect but then he told me hes been pretending and I asked him since when all he said was for a long time now and all I can think about is like is there someone else was I good enough obviously I wasn't

I thought everything was fine especially since this pass year all he kept talking about was us getting married(have a ceremony because we didn't do one )and just future things and we go out to the park have picnic dates take our son swimming we were just having a blast well the lil things u can do with the whole covid situation rn

And now it's like everything changed I'm so confused i dont know how to feel or show / act with my emotions I just want to cry and sleep all day but I cant cuz of my son so I'm trying to be a good mom but with what is going on i dont know what to do

***(I have told him many times before if hes not happy pos the door is open because I dont want him to be trying just for the kids and not us because at the end of the day me and him wont be happy I thought everything has been good since we fixed things 1½yrs ago when he cheated but now with everything makes me think what if hes started again and now makes me think he messing around again)

I just need to vent thank u for who ever read the whole thing