I don’t want my poor baby to have a broken home and suffer the emotional consequences like I did with my single mother.
Good!
Your baby never had a 'mended' home so cannot have a 'broken' one.
You are providing a home emotionally, financially, solo - your baby does not live in a broken home, they live with their mum, who loves them & is capable of providing for them.
You are not your mother, & you have learned what not to do as a single parent. You & your baby will be just fine.
My sons dad has started to send me money and says he really wants to do more and be a better dad.
Your ex can continue to contribute financially & become a better dad.
He doesn't need to be in a relationship with you to make that happen.
Stop holding yourself hostage like this.
Millions of women raise their kids solo. There is nothing wrong with it. You have nothing to compensate for, & you do not have to sacrifice yourself to a man in order to expect a decent level of parenting from him.
You got together with ex very young.
He wasn't ready for a baby - you were, & you have stepped up to the plate.
He doesn't want to have sex with you, & has serially cheated.
This man IS YOUR EX! - You have no need to hang on out of misplaced "hope" that you can be some kind of idealised family image with him.
You have outgrown your ex. You have proved to yourself that you can hold down a job, mother your child, & have a life without him.
I say embrace it, & move on.
How he steps up (or doesn't) as a dad & provider is up to him - it is not your responsibility to provide handholding while he catches up (or doesn't).
Move on with your life, & your ex can be a co-parent.
Congratulations on your strength & maturity 