Am i the problem?

I feel so down lately, and I dont know what this is anymore? am I just lying to myself becz the hardest thing is letting go please help :/?
Me and my bf for 2 yrs started off really good he chased me, had me, but somewhere along the line, he stopped trying. We were like 2 peas in a pod. During the first yr- Since I met him I had heard he was a womanizer, - I found out he had been flirting with countless girls and he stopped becz I brought it up he did the whole- I dont want to lose you thing. (Note:why I have trust issues with him) so we tried it and worked on us. Now here we are almost 3 yrs in and we are together for most part of the week, but when the weekend comes around (at least the weekend he doesnt have his daughter) he always tells me hes going with friends, which I was fine with at first but after weeks of it, I finally said that I dont appreciate how when i always hang out with him, its at his house or with fam. At first I felt like he was committing, boy was i blind. we hardly go out together, like to have fun. I told him I would like to be out and have fun with him so we tried and I got upset becz the entire time he ignored me he never came by to ask me how I was doing or enjoy some part as a couple. I confronted him that night, he told me thats y he doesnt take me to avoid us fighting, he said he cant b the typical b.f that is always next to me. Thats why he dnt invite me because he wants to b free to walk around without having to be restricted. he does nothin to chang it! We say we r through and I leave then he tells me he doesnt mean it that hes sorry, he will change and then the same cycle :/

what my prob really is becz he acts like he cares so much, but I feel is afraid to show it. And he has told me he is scared of falling in love and then it goes wrong. It hurts me becz i told him in the process hes only hurting me. when we argue he says hurtful things and ive told him we may argue, I may say things but never forget how I feel about him Unlike him, an I hold resentment towards him. He tells me I know where the door is and if im so unhappy to leave becz hes not going to change for anyone.. or hes not gonna beg no girl that he doesnt have me their by force and does he r really think hes gonna cry over a girl, theres more where i came from. He said he invites me to family get togethers becz he knows we wont fight and his daughter will b there if not he would have done his own thing if his daughter wasnt there. Then like I said he says that hes just angry and cant stop his words and I forgive him every single time. Then wen we are ok I start blaming myself and the guilt sets in like maybe I am at fault. I do this to our relationship why can't I just be happy.
And I do want to add that in general he has not cheated (have sex or w.e.) but hes a flirt and he does it over social networks. For example Instagram, ive seen it he likes a crap load of girls pics and i tried to be like oh its w.e. its just pics. But something caught my eye one day and it was because this female was constantly on his I.G. so I went to her page and I seen he did the same to her, it fired me up. I confronted him and her becz I didnt like it. He said to me "bby shes a friend I want u im sorry", . I told him u make me look so stupid to others im counting on u to support me the way I do to u, I shouldnt have to make our relationship known and shes feeling like ur leading her on, cz its not one or 2 pics u like ur all on her thing. So she sees it as u have her attn. So I cried and told him that I loved him and if its not one thing its another with him, like yes I disagree with many things he does because he does them carelessly and if it were me doing them he would have left me a long time ago. He said sorry he didnt do it to hurt mw. So I obviously expected him to stop and he hasnt he still Likes her pics and does what he does like if what I said went in one ear and out the other :/ or like if him telling me she was just a friend made it ok! Its anger and hurt but more with myself cz I dont know how to leave him becz its not always bad but for the most part it is.
I feel like im going crazy, becz if it were me he would Leave or yet when I dont answer his calls hes breathing down my neck or if he sees me driving on a street he'll catch up to me to see whos in my car, he tells me he domt know what he would do if he caught mw cheating and gets mad when guys comment on my I.G or axknowledge any guys.
I do get upset when he goes out, I know I cant stop him from cheating but it hurts my heart becz I know hes a flirrt and a part of me is so scared that hes gnna cheat. And thats why he always needs his "guy time"