Not knowing where you live, and you needn't post that info. openly, I'd suggest calling what would be akin to either Department of Health & Human Services or Adult Protective Services. Please, don't think as I did and that Adult Protective Services sole role is abuse-related. It also may provide social workers, and help arrange for in-home visits, accompanying/driving to appointments, etc.
Too, one of the agencies should also be able to provide you with a list of local services available to you and to your Grandmother -- such as in-person support groups, as well as adult care services (some that aren't fee based, although most may be).
".... This world wasn't built for people in wheelchairs ...."