Overthinking

I'll start with a very abbreviated background: A year and a half ago, my fiance rolled a full dump truck off the side of a hill when a tire blew. He's still going through surgeries and therapy, to which his retired mom takes him so I don't have to take off unpaid so much from work. His dad is in beginning stages of dementia, and gets very upset when they leave him home without a car in case he wants to go somewhere (he never goes anywhere, though). So our solution was to buy me a car with a 3rd row seat so I can take all the kids and grandkids places, but leave that car in Mom's driveway till the surgeries are all done, then It'll be parked at our house.

Well, I've been driving my adult son to and from work for 3 weeks now because his transmission went out and the shop is being super slow fixing it. Middle of last week, we all agreed that I would let him use my normal car, and I'd drive the 'extra' car till his is fixed.

Here's where my overthinking and taking things too personally comes in. This morning, my fiance told me his mom was briefly upset that the car wasn't being used as originally intended. This upset me, and I've ruminated all day about how we should just take it back, get my car back from my son, and I'll just drive him around for another week or 2. It's easier for my emotions to leave work to ferry him around at 2, and go back out to get him at 10:30 pm every day, than to feel like I'm causing any tension or strife to anyone. Fiance says to just keep driving the 'extra' car, and don't worry about it, since his dad has no business driving, anyway.

I know it's all ok, and it's nothing against me personally, it's just a frustrating situation, which is supposed to be over by the end of this week. I just needed to tell someone, to get it out of my system. Just vent, I guess