Not eligible for limited capability for work because I'm on a joint claim

Help,

I am not eligible for limited capability for work because I am recently on a joint claim with my boyfriend. The problem is that he doesn't contribute to my bills or my rent.

We live in a house share, we have separate bedrooms, separate contracts, separate rent and bills. I was forced into making a joint claim because they found out I was living with a boyfriend.

He works 40 hours a week, I work 8 hours a week... 

This is unfair, I'm the one who is disabled and cannot work full time...