You have no claim on any of your partner’s assets unless you have contributed to them physically or financially in which case you may have an equitable (financial) interest.
It would be different of course if you were married.
He has no liability to pay you any spousal maintenance (for the same reason) although he does have a liability (if you break up) to pay child maintenance at the statutory rate which you will find in this booklet. Start at the top of page 18 which gives the basic rate and then the rest of the booklet has the adjustments.
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/672432/how-we-work-out-child-maintenance.pdf
in respect of providing for you (not the children) I’m afraid that you are on your own and you would not be the first person who stayed in a relationship quite simply because they couldn’t afford to split up.
You may be entitled to housing benefit and/or income supports and/or tax credits but I am not a benefits entitlement expert.
Can I clarify anything else for you?
I am happy to answer any specific points arising from this.
Please take a moment to look at the top right hand corner of the page and rate my service by clicking one of the stars at the top of the screen. It’s important you use the rating service because that gives me credit. It doesn’t just give me a pat on the head! Opinion, (Although there is an incentive scheme where the more five-star ratings I get, I do actually get a pat on the head! :-)) All you need to do is press Submit. Thank you.
If you still need any point clarifying, I will still reply because the thread does not close.
Best wishes.
FES.