Minimum wage? Or more? Any savings, either if you?
Do you share income as a household, joint account etc? If not, you'll probably be better off long term to sort out your living situation as a single person so you can claim means tested benefits. As far as DWP is concerned, you're pooling resources, regardless of whether you actually are or not.
If you're too ill to work and he refuses to pool resources with you, that's financial abuse. If he doesn't want to live "as if you're married" then you need to live separately, because DWP doesn't acknowledge households where you're committed in terms of monogamy but not committed in terms of pooling resources financially. In DWP eyes, you're essentially married, even though legally you're not.
That doesn't mean you have to live alone. You could live with family or friends, these people aren't considered your household for benefits/income purposes. Only spouse/partner and dependent children is your household. Everyone else is financially separate households even if you live in the same property.
If you're looking at private rental you'll need to know the Local Housing Allowance for your area (Google it). Entitled To website can give you an idea if what you'd get in benefits. Input the hypothetical situation you'd hopefully be changing to, not the current situation you're in now (although you can do that too).