Any advice regarding caregiver support services in NJ? How about elderly depression?

Hi, I'm a 49 year old male caring for my 82 year old mother. Until recently she was still functionally mobile and could perform most of her simple daily tasks herself or with a little support. Then around a month ago she started taking a BP medication that she was taken off of a year ago (which I didn't even know she still had) and the result was a period of extreme tiredness and lethargy. After identifying the problem and cutting that medication off she's shown marked improvement, however she developed some terrible habits during that period which haven't subsided as her overall health has improved.

She was just checked out from head to toe and aside from her chronic arthritis issues she's doing rather well health-wise. But the recent setback with the meds seems to have completely ruined the mobility she enjoyed just a month ago. The measures I took to help her during that period of diminished mobility seem to have backfired on me as now she won't make any effort to perform the simplest tasks. Even helping her change her adult diaper in the morning has become a huge chore as she refuses to assist me or move herself in any way. Just getting her to get off the sofa for a few minutes ends up being a half hour discussion of the importance of exercise and etc. She'll "yes" me half to death then ignore everything I said. She does the same thing with her visiting nurses as well, she'll "OK" and be genial and agreeable then as soon as they leave she goes right back to doing nothing. I've tried to give her tasks to keep herself occupied (which she has requested and claims to greatly enjoy) then she'll ignore them in favor of staring at the TV. She was always a big reader and I've gotten her books she requested from the library and they sit there unread. Even the measures I've taken to give her some peace of mind (like adult diapers which she never needed before) seem to have backfired as she seems to be using them as excuses to avoid activity.

I work from home which is very helpful, however over the last month I am literally having to wait on her constantly. For example, she'll complain about wanting a drink and it's right there, six inches from her hand yet she wants it handed to her. Helping her get dressed has become a lengthy chore as she won't even try to bend a knee or even stand up a little straighter to make it easier. It's literally become every single thing, even changing the channel on the television has suddenly become too difficult for her to do.

Assisted living is out of the question, no resources and she steadfastly refuses to leave her home. Her granddaughters help out a bit but not enough to really lessen the impact on me. I feel terrible about feeling this way but the stress is slowly crushing me. The lethargy and lack of exercise has caused her to gain weight as well which makes it even more difficult on me. Just this morning I was helping her get out of the chair and onto the sofa and suddenly she just went limp and became dead weight even though she'd just been "resting" for a few hours. As much as I wish to help her and as much as I want to keep a close eye on her overall health I just can't spend every waking moment fetching things and destroying my back every time she needs to move. Does anyone have any advice on dealing with depression re: the elderly? Is anyone aware of any support available in NJ for folks in my situation? I've started to investigate my options but here in NJ it's all phone tag and endless waiting for anything to happen.