Been car free for a decade now, and I love it! Strongly recommend. Couple things to think about:
1) Trying on the car-less life, as recommended by a previous poster, makes a lot of sense to me. Spend a month never using your car, see how it feels!
2) You mention the vet. That was something I worried about, as I have two cats, and figured I’d use Zipcar for that. Turns out - regular cabs are happy to take animals in carriers. Have never had one pass me by. So that may be less of a deal than you think.
3) The one thing that used to drive me nuts was donating to Goodwill. I hated throwing away perfectly good clothes, but I wasn’t willing to shell out for Zipcar to drop stuff off. I’ve since discovered
https://www.givebackbox.com/, and it’s been great. You basically mail stuff to charities, and corporate partners pay your shipping.
4) Zipcar (or presumably other car share services) didn’t end up being worth the money for me. There’s an annual membership fee, if you’re going to a social activity where you’ll be there a few hours it gets really expensive really fast, and I found I was only using it once or twice a year, so I cancelled. Instead, we do traditional car rentals fairly often (4-5 times a year?) and find that’s more cost effective. You can generally get a Budget car rental for $30-40 per day, no annual fee, and you can pick cars up from Union Station or National Airport, both of which are right on the metro. Sign up for “Fastbreak” so you can skip the counter.