Income Related ESA - joint or single claim?

I have been in receipt of ESA for three years and now in contribution based bracket. I am also in receipt of DLA, and my husband receives CA. However, my husband has been diagnosed with tumours in his bladder, needing surgery. I rang JC+ to enquire about change in circumstances, but this was not really helpful over the phone and she mentioned my husband applying for income related ESA, and perhaps having a joint claim. I don't know what to do, as we cannot afford to be any worse off than we already are, and wonder what the best way forward would be. Do we continue on our existing benefits, or put in a new claim, and is a joint claim more beneficial in the long run?

An appeal has already been put forward for my ESA.

I would appreciate firm advice please!

Thank you Gordon for your very kind advice and recommendation. I will certainly contact the Welfare Rights.