How old is your mom? She might be going through menopause so that's gonna affect her mood greatly.

If you're having problems with the car, try to see what's wrong with it, like what kind of noises it's making(or not making)or any other things that seem off and post your problems on a board where there are auto experts.

I think that the internet e-thug got to you because of all these problems that you're experiencing and all that stress just kept piling up. My guess is that you just snapped, so don't take what the guy said too seriously. I think you should just take a break. Since you live in Argentina, I'm sure you can go take a trip to the mountains and get some r&r