Hi Jedi67,
I think I can relate, at least somewhat.
Does your mom live alone?
My mom has lived alone. For the past 8 years, we have been living together in a large home. As she ages, she needs more medical appointments. I enjoy helping her and truly do want to be "in on" her care. It's becoming increasingly difficult to attend to her needs in this way, as well as to attend to mine. Sometimes hers, alone, keep me exhausted and I cannot get my things done.
I have siblings; yet, only 2 live nearby. My brother has never helped with my mom and likely will never do so. My local sister works full-time and owns a very busy business. It is truly very difficult and/or impossible for her to help out. That leaves me. I am totally medically disabled. I have several disabling medical conditions and then the PTSD and BPII, etc., as well. I try my best. I can see where this is going to have to change some though. I just cannot keep up with it all... and take care of my own needs as well.
I do not get any support from my local siblings. Absolutely none. I am often criticized by them.
I do get support from a sister who lives in a different state. I deeply appreciate her support.
My mom does try to lend support. She does try to understand. I do not share my psychological/psychiatric info with anyone in my family, save one sister. The criticism would just get worse.

There has always been a lot off jealousy among certain siblings and they have carried it over into our adult lives, unfortunately.
My mom can, sometimes, be a handful. I find she has an increasingly difficult time recalling what doctors have/have not said to her, etc.
She also tires very hard to use a computer, to have email, to contact her friends and doctors online, etc. She also still uses a cell phone in a very basic way; yet, still does it!

She needs a lot of help with electronics of all types and can/does get herself into a lot of trouble by messing with things she does not understand. It often takes me hours to fix things she has messed with at times.
While she does do a lot on her own, she needs assistance with more and more. The trouble is: so do I. I am recently separated from my H. We used to do a lot together, including tasks, transportation, cooking, errands outside of the house, etc. So there is an even bigger burden right now. I have just found a handyman to help with a few things. I am also looking for other types of help.
Setting boundaries? Yes! Have to! I have been setting more/different boundaries with my mom and with others. With my mom, I am setting up "office hours." She can bring her many questions, her mail, her medical info., etc. to me on a given day(s), between the hours of 9-12n. We will make calls then, etc. If she has anything urgent, I am right here for her, of course. If I do not set up a time/day in order to go over all of her "stuff," I find I am going over it for at least 4 hours almost every day.
There is not enough to keep one busy for all of those hours/days; yet, she forgets to write notes, forgets to files things, etc, necessitating we deal with the same items over and over again. So I am working with her on her attention span and am trying to keep things done in a manner which is helpful to her; yet,make it all is as efficient as we can make it for both of us.
It sounds like you have a wife and family to attend to, in addition to attending to your own needs. It is wonderful that you care about your mom, of course.

Yet, you DO need to attend to your needs and to your family's needs.
Is there anyone else available to help your mom?
Family, friends, neighbors, church friends, friends from social groups, other?
Is there a way to give your mom some attention without letting her take over your life?
I have found it helpful to think about what my mom can and cannot do realistically. Sometimes people want us to do more for them or more with them than they truly NEED. While it is "nice" to be there for them as much as we can, we can identify the events/activities when they absolutely do need our assistance/company.
For example: I might attend medical appointments with her when she is seeing a specialist and/or the medical issue is more complicated. I might skip an appointment with her primary care doc, where she will be getting med refills, vaccinations, etc.
I strongly encourage her to keep up her friendships and to attend as many community events with them as possible. She loves this and has become the neighborhood social director. YES! This means that I have time to use however I wish. It is a win-win. She is also very active in the area senior center and has become one of the "leaders" of that social group. I just have to be careful that I am not sitting at home doing her accounting while she is out partying.
For our retired parents, especially those living alone, it is important to encourage them to attend social activities, including senior centers, day programs, etc. Not only is it healthy for them, (they will likely find some support, some friends, etc.), it gives us some freedoms without feeling guilty.
I, personally, have given up on ever expecting my siblings (save my very understanding sister)to understand, or to even be interested in my medical/psych challenges. They just cannot reach/think outside of themselves and may never be able to do so. I have come to terms with this fact.
I have also fully realize, that at this point and time, my siblings are not available to help with our mother. Once I'd accepted this, it helped me to move forward in securing some options that might fit her needs, as well as mine. I have found it is too easy, and so not helpful, to stay stuck in the place of trying to get others to take an interest and/or to pitch in. That is a huge mud hole that just keeps getting deeper and deeper. Assess needs, learn about options, be creative, work toward getting everyone's needs met as efficiently as possible. Oh... and... enlist any help that is available.
Ultimately, your mom, unless she has been ruled incompetent and/or is somehow totally medically disabled and cannot help herself, is responsible for herself. It is okay to gently remind her of this. Oh... she might also look at the Council on Aging in her city/town/county/state.
Do set limits! It is healthier for everyone! Teach your mom to appreciate anything you can do for/with her.
I feel like I wrote too much. I will leave it. It might help someone. Besides that, I need to go and get dinner.
I love having you back around!
My Best to You and to Yours!

P.S.: I also make some trade-offs with her. If I am working on "untangling/unmangling" her computer, for instance, and it is dinner time, then I ask her to cook dinner while I am working on her "stuff." You might be able to work out a "trade" of some sort with your mom?
LOL! My mom used to give me her "stuff" she could not fix/do and then would take off to go meet friends or to do something much more pleasant. I now have told her that I will not work on her "stuff" if she is not here to learn how to do it for herself and/or here to be doing something else that needs to be done in the house.