It is difficult to leave, you don’t deserve to be going through what you are. I agree with all posters that are suggesting you need to leave him, this does not mean it isn’t difficult. To those writing what kind of parent are you, OP is obviously a parent doing both roles. You all mean well but this bashing does not help someone who already clearly has self esteem/confidence issues. It is easy to say these are excuses to not leave but a drug addicted gambler, drunk with little education. I’m sure he would handle her leaving him well, no of course not. OP could be very scared to leave because of how he may react.
Families can be relied upon but to be that clueless (this is not aimed at you OP) that there may be other factors involved where OP family can’t be relied upon full time or depending on the family background how much they’re willing to help. Again, it isn’t as simple as ltb.
Op you are under financial strain, you may be able to get some more help of the government to see yourself through until the 2 year old is at nursery, if you have free hours you could use them to free up some more time for you to be able to work. A childminder is also a good idea from what another poster has written, it could be worth seeing how much they are. Right now, if he’s unemployed there’s no point for you to stay with him. His money will run out and he will turn to you on the little money you have and you will be left with nothing.
Leaving any relationship is difficult, but a man who you had children with is even harder. Having that conflict of protecting the dads image for your children and when you are to leave the back and forth childcare between you both, if he cannot be trusted is an extremely difficult battle. However, it isn’t your job to protect his image, even for the sake of your children and that’s something you need to remember if you are to leave. There are people that can help, and would want to help.
OP you deserve to have a life without this much hurt, toxic relationships can really affect your ability to have any self confidence once you’ve been shut in dealing with the things you have, take it step by step. Try to work on your self esteem, from what you wrote it seems like you’ve always had quite a low self esteem because of how much you’re tolerating.
You’re doing a good job raising both children on your own, you’ll do an even better job once he is no longer around.