Disability allowance means test

I get disability allowance and my partner works. We just had a baby and will be living together. Since the disability is means tested, I’m so worried they’re going to cut my money completely. I have nothing else and really don’t want to be reliant on somebody else completely. Will they take into consideration my partners outgoings in the means test? Like the rent he pays? For example he makes 2400 per month but pays 1000 (soon to be 1200) in rent and also has other bills like utilities and insurance etc… That doesn’t leave much at the end of the month and surely we can’t all be expected to live off what’s left of that alone? So does anybody know if they will take all of this into consideration? Is anybody else here on disability allowance, living with their partner and were able to keep their money?