extremely insecure husband..

my husband and i have been married going on 6 months. he is 25 i’m about to be 23, we have had two separations since being married. the first one because i had just given birth to our baby, i was in a bit of postpartum funk and he took it all wrong like i was just always pissed and irritated so he said he had enough and took it upon himself to call himself “single” on facebook, (very immature ik).. his birthday was just 3 days away at that point and in my mind i knew he was going to be going out drinking and doing who knows what else. i find messages on his facebook between him and an ex saying he left me for her snd he missed her and wanted to meet up on his birthday. i told him what i found and he played it off.. fast forward two weeks later and he goes through my phone to find a guy friend i was messaging on snapchat. and he slapped me up a few times and i fought back hitting him too. so he left and we agreed we needed space. so a week later we talk it out and say that we should at least try for the kids and we agreed to get off social media i deactivated my facebook and sc on my phone, how ever my fb was still logged in on my ipad and he just found out today from his cousin. so he throws his wedding ring off on the freeway and says he cant trust me. i told him he can have my phone that i have nothing to hide and we can switch phones for a few days just to prove it to him and he says no. he said we can still try for the kids and leave it in gods hands to fix but i dont feel thats enough, he says he looks at me differently now because of the things he saw on my social media, but i do too i just forgive him every time bc i love him so much. but he cant look past the messages he saw... mind u when we were on our break he went to a club and told me some girl kissed him.. me i went out and wore jeans and a crop top and he said i was being slutty. so tell me somebody what can i do to save my marriage i know reading all of this it sounds soo immature i know it is. its silly things that can be worked on but what can i do about his insecurities. i feel like it wont get better because he said his trust for me is 50% now.