MissC... and you are going to get your siblings to help you with your mother I hope.... Sweetie, it's all stress, you get run down, you are more vulnerable to viruses et al... You can't do everything. Ask for help. Please
Ben Don't be envious of the BMW - it costs $100 everytime I fill the tank

($1.64/L) It's an awesome car but it's a PITA because I worry about people scratching it in carparks etc.. I miss my old bomb (Ford Falcon station wagon). Man I had some good times in that car
Ask the mechanic if changing the gasket will cause other problems - with the increase in pressure. I always found that whenever we changed gaskets, the problem went right through the engine - and we had to change a lot of gaskets - BUT then back in the day, we had gasket paper, gasket goo and would change our own gaskets (which wasn't that hard). it's a shame you can't car pool with your ex, and save the money.
I no nothing of your personal finances, but what I do when money is really tight, is to track all my expenses for a week, and then sit down at the end of it and work out if the expense was worth it/the reason for the expense.
E.g.
Coffee - $5 (needed to stay awake, but should have bought my own from home)
Lunch - $10 (could have brought my own)
Chocolate - $2 (stress made me do it. go for a walk instead)
Petrol - $40 (needed it to get to work, will drive better, explore car pool/public transport)
And then the next week try to avoid those splurges and sometimes, I'll put the money into a moneybox or hide it somewhere in the house.. In the example above, i could have saved $17 in one day.
Sorry for telling you how to suck eggs.
Versus or should I say Kitty hair. Hugs dude. Sorry to hear the last few days have been shit. It will get better. PM me if you wanna talk, or just vent or whatever