OP he should have his own money anyway, he wouldn't be destitute if you reclaimed yours.
You should have all your wages and child related benefits/low earnings benefits (delete as applicable) paid into your own bank account.
He should be claiming unemployment benefits or disability if he's "too depressed" to work. (He's not too depressed, he's lazy and wanting you to pay for everything and also wanting to deprive you of money so you can't leave. Has he even been to the doctor about his "depression"? I'll bet not.)
If the tenancy agreement is in your name, tell the landlord you want to end the tenancy, get your wages etc changed over to pay into your bank account and get a new flat lined up ready for payday, for you and DC. You don't even need to tell him, as soon as payday arrives and you've got some money get out of there tell landlord you've left and don't tell your boyfriend your new address.
If the tenancy is in his name it's even easier because you've no need to give notice to the landlord. Just find a new place and leave as soon as possible.
If rental agreement is in joint names you're best bet is probably to tell the landlord it's an abusive relationship and you're leaving him, so you need removing from the tenancy. Asking the landlord not to say anything to your boyfriend until after you've gone.
If you contact Women's Aid they can help you with all this. From finding you a place in a refuge if you want, or helping you get on the council house list, getting grants to pay for furniture or the deposit on a new private rental place if your wages are low. They won't make you report anything to the police and they won't make you leave him if you're mad enough to want to stay, they won't judge you for it either.