Can Sun Life discontinue my claim for not using the advocator group?

I don’t mean to sound like a big baby here. I know a lot of people with Sun Life have it worst than I do. Sun Life did approve my LTD claim and I have collected LTD for four years. However, can they really say that if i don’t file a SSDI claim using The Advocator Group which is their “legal department” that they could discontinue my benefits? That seems like a threat. Our appeal from the Hearing was denied and what we are/were appealing is medicare benefits and this appeal has been ongoing for two years. Nothing about my benefits. So I would get no SSDI benefits, no back pay, and I was told by the attorney that Yes, we are also we are appealing (seeking) benefits/back pay, and dependant benefits. None of which were true. I didn’t find this out until our next Hearing, with yet another different attorney, that the appeal we were there for, just has to do with Medicare coverage. I already have great health insurance so i don’t understand at all what the point is. I have 9 compression fractures in my back, DDS, osteoporosis, I’ve lost three inches in my height. I also have Rheumatoid Arthritis, asthma-copd, a history of cancer times 2, knee replacement needed on both my legs, depression, and some other really embarrassing things. I’ve been hospitalized 4 times since October of 2015. Should I start looking for an attorney now before they discontinue my benefits or wait? Could you tell me…Would your firm be interested in my case and what is your fee?