What a nasty fucking user!
You're being financially abused.
50-50 on the bills, but about 90-10 to you when it comes to all the extra work - childcare, cleaning, cooking etc, especially childcare - which makes it impossible for you to earn a similar wage to him?
He's either gambling or probably is building up a nice little nest egg somewhere at your expense. Probably for a house which your name definitely won't be on.
He isn't a good dad. He's an absolutely shit dad who sees himself as not part of a family unit but is out for himself financially, making sure he's ok at the expense of his child and their mum.
I would suggest this.
Sit down with him and tell him that you've had enough of the financial inequality. Basically, he earns more because YOU FACILITATE IT. You earn less because you take on practically ALL of the other responsibilities he should be sharing in as a person enjoying family life - childcare, housework.
Tell him he's got two choices. Either he steps up and does 50% of all the ACTUAL work in your family life, so that you can earn more, take on more overtime etc and then FAIRLY contribute that 50%, or he starts paying at least 75% of all bills to reflect the fact that he earns more because your extra work makes that possible. If he won't do either of these things, then the relationship is going to have to end. Remind him that one thing being financially fleeced by him for so long has taught you is that yes, you can manage without him - and you'd actually be better off if you did :)
My bet is he will refuse. Start packing and arranging - and go if he doesn't cave.
If he does cave, it will be paying more rather than taking on responsibility, because as said above he is an example of a fuckign bottom feeder parent. If he does this, smile and say great! - and spend six months or so getting your savings looking better and then leave him anyway.
Even if he were not a financial abuser, this relationship has run its course. You're only there because you got together so young you have no idea what a good life looks like. It isn't this. He is lazy, ignorant, boring. It isn't you. Don't waste your life with him.