Pregnant and depressed !

I’m 23 weeks pregnant and I am so depressed I literally hate myself and I absolutely hate my life I have a 4 year old and another baby on the way and even though I do feel excited about a new baby I don’t actually feel happy , I’m so scared to go through this again, My first pregnancy was horrible I used to cry a lot and my boyfriend was never home he was always out and about drinking with buddies he would leave and come back till 2 or 3 am , he put me through a lot of shit and he almost left me for his ex I seen a lot of shit in his phone I should’ve never seen while being pregnant !! I saw pictures of him and his first girlfriend of him pretending to go down on her she had underwear on but his tounge was right by the V And i saw pictures of her in her underwear & it hurt so fucking bad but being young dumb and pregnant I didn’t want to leave the one man I felt like I truly loved , Then not even a week later I saw another pictures of him and another ex actually having sex !!! She was sitting on top of him but they were both sitting idk what the position was called at first I thought it was one of those horny pictures on fb cause it had a filter and it said “ I love you” I didn’t really get mad until I recognized the room ! It was the same room I was sleeping in during my whole pregnancy and fuck it destroyed the shit out of me , I can’t even have sex anymore because I think about that picture and I want to cry , Then two weeks later I noticed he was texting another one of his exes and I found out he was asking her to fuck and that he wanted her and not me even though we were living together and I was prego but once again I was stupid enough to stay ! When I confronted him he stopped contacting her completely and swore on our unborn babies life they never even met up that they were just texting and he would say those stupid things when he was drunk ! But I didn’t leave him and god I wish i fucking did but I really felt like I couldn’t even though he treated me like shit my family treated me way worse then him and I didn’t have their support what so ever my family is super toxic and were all separated and don’t speak at all , my boyfriend is 6 years older then me so he had many girlfriends he was with for a while and me I never had nobody serious at all ! He was my first serious relationship so all this I saw with him broke my heart , when our first baby was born he completely changed he turned into a decent man and even deleted all social media but after 5 years and a second pregnancy our life is still shitty we don’t live together anymore we’ve been living separate for 2 months now and we hang out almost every single day but some days he just stays home , I feel like I am severely depressed I cannot get over everything I went through in my first pregnancy and now being pregnant again I just remember everything I went through , its horrible to say but I have had bad thoughts with this pregnancy like hoping I died at birth and my babies stayed with their dad & other days I feel happy like abnormally happy , But the truth is I’m not ! I’m lonely I have no family to go to , I have no friends and I can’t trust my baby’s father , He’s an amazing dad he treats his daughter with so much love and respect but when it comes to me it’s just completely different , I feel like I am alone in this , I have no job and I can’t really even work I have placenta previa so I can’t do anything and I completely depend on my baby’s father & I hate it ! I have been used and abused my whole life especially by my mom! She always treated me like shit like made me do everything she was supposed to do like take care of my two youngest brothers , clean , cook , feed my dad , I would even give him his clothes for work or for when he was going to take a shower , They never let me go out and if I did i had to take my brothers with me , I had a best friend who was my neighbor and every time I went outside I had to take my sister with me even though it was literally right next door , My brothers did everything they ever wanted and I was literally always home so I feel like that’s why I ran from home as soon as I hit 18 , I’m 22 now and my parents still care more for my brothers then they ever did with me , When I say I’ve been through some shit I really have ! I was sexually abused twice once by my uncle and the second time by someone that worked in my high school , so I just feel like I’m mentally fucked up at this point