God grant you the patience of Job.
What does your Dad think about the situation?
He hates it, but like I said he's working himself to death. Most days he comes home, eats and falls asleep because he's up at 6 in the morning to be at his job by 7 so he can get the shop up and running and then works hard as a lead mechanic until 5-6 at night. He can barely distract himself 2 nights a week with booze and pool tournaments. He's 55, he's put his body through the wringer and is damn near a chain smoker (Something Mom and Grandma don't help with, the amount of stress they cause everyone.) and he had to fight for years to get his pay raised to $22 an hour for a job he has over 30 years of experience in AND being the guy who trains all the newbies on top of everything else he does.
Doesn't help that his own mom passed at the end of August and we're dealing with all of that even now, and before she passed we were dealing with her multiple times a week for doctors appointments and grocery runs and so on. Those would be all day affairs, when really outside the Appointments it should only take maybe 2 hours, 2 and a half max.
Frankly, dad doesn't have the energy to give a shit, and I don't blame him.
So your mom is probably about your Dad's age or a little younger?
It sounds like your mom is young enough, should be taking care of her mom and you should be out doing your own thing making the most of your own life. Your Dad lost his mom, I lost mine about the same age as him and we were close. If they were close, one never really gets over the loss of their parents, they just have to learn to live with it.
I don't know. Getting a part time job would get you out into a more positive atmosphere a few hours a day and help you to emotionally relax a while, meet new people and make some money while doing it. Not being home will force your mom to be more involved with her mother, and maybe both will appreciate you more when you are home.