Why is he acting all horrible all of a sudden?

I know I should just dump him technically speaking but when you love someone properly you seek out reasons for why he is acting a certain way etc.

First off, I am pregnant - nearly 24 wks gone and 26 years old, v miserable and alone, working my bum off in Ireland, to try and get money up for the baby as I doubt he will give it to me at the end of the day and I don’t want his money anyway..he on the other hand, is in London - trying to set his new business up and is 34 - he has been on unemployment benefit for last 5 years - is living in his parental home and refuses to come to Ireland to rear the child with me. On the other side, he offered me a room in his sisters house but wanted me to pay her a housing benefit as a form of rental income. I flatly refused..and my mother gave out to him and accused him of wanting to commit fraud.

So since this, I have stayed here and am doing ok apart from the fact I have bought everything for the child and got nil support from him..I made this point to him and he gave me 40GBP half the price of the buggy I bought..as he did not want to be accused of not pulling his weight even though he still isn’t. He keeps upsetting me and I try to not let it get to me for the sake of the baby..today I try to understand this behaviour..one min he is great the next horrible. He calls me untrue names like slut etc..and is v disrespectful even though I would not even dare cheat on him..but he has it in his head that I have already done so..eh nooooo I haven’t and even if I was offered I wouldn’t bother or want.. but he is powerless to see this - he is unable to trust and wants DNA even for baby still..even though he knows deep down its his..I dont mind that..if that is what he needs on paper to see its his..fine I am not worried..but why disrespect the mother of your child? I threatened to leave him today..that for me was progress..but I am not strong..and broke down into tears and hung up on him..espec after he said I dont know if I can ever love you to be honest..he has been thinking of contacting his ex Paki married girlf. I said in anger, why do you give more of a about her than you do of me? He tried to say she is an angel in comparison to me!! I said well if she is a f~~kn angel then why she dump you and run off and marry someone else..he wants to contact her to find out if she got divorced..I said is that why you act horrible to me..you try to push me away from you to go to that b##ch..but he told me to f off..I said fine I f##n will..but I broke down as I sent him a gift to mark 1 yr of relationship…so I said..do you just get some kick out of hurting me..I just don’t know what to think..and being pregnant blocks me from thinking straight..

What I want to know is..do you reckon he doesnt give a about me..wants her so acts crappy on purpose with me..or is fed up of being with me so wants out..and a way out of his responsibilities of being a dad? I asked him all this but he denies it..I said just dont lead me on..if you dont love just bloody say..so today he finally killed me and said I dont know if I could ever be capable of loving you..imagine after I just bloody bought the ungrateful man a gift..I said you could have said thanks..a simple thank you is that too much to ask! so..anyway sorry if I annoy you and rant over..your thoughts would help me to be stronger..I just cant think straight..dont know if its hormones or what..

Thanks..