Then you are every bit as bad as he is! You are being just as selfish as he is, but in a different way. And more calculated.
He is lazy/thoughtless and you don’t appear to like him, far less love him. You view him with utter contempt. You do not think he is a good father. You don’t think he is a good husband. You don’t seem to want a relationship with him. All quite possibly totally fair. And certainly, it seems like he has his failings.
However, you have chosen not to have a serious discussion (or another one, possibly) with your husband about the fact you aren’t happy and this relationship is not working for you, perhaps looking at ways you could work on it (if you want to). If you don’t want to address your problems, or work on your relationship- or, if you have tried and he won’t make changes/work on the relationship and you’ve had enough- then you should end your relationship. It really is that simple- work on it together, or if you both/one of you can’t or won’t do that, end it and move on.
Don’t bring a child into this mess, it’s not fair to them or the child you have. They will pick up on your resentment and contempt for their father. They will see his lack of effort. None of you will be happy. Or you are bringing them into a family which you already know will be split because you intend to leave him the minute you get what you want.
Altogether, it’s a pretty despicable way to treat your husband- even if he isn’t perfect/- you are simply using him to have a child when you don’t want to be in a relationship with him/actively dislike him (but presumably haven’t told him the extent of your negative feelings?). You are using him to get what you what you want- another child- without him having full knowledge of your feelings towards him (or possible intent- ? To leave as soon as you have a baby). That’s not the kind of thing you use another person to achieve if you have any integrity. It’s just wrong- use a sperm donor if you must- at least they are aware of what they are signing up for. I’m sorry if this seems harsh- but I think using another person (especially someone you must have at least cared for at some point if you chose to marry him) to have a child is wrong.
I’m not saying he is without fault- it certainly sounds like he has the fair share of blame in this failing relationship, and is clearly not always treating you well and supporting you as you need. But I think what you are doing is worse.