Am I in the wrong

So we have one car (my car). my bf uses it for work since i’m a sahm. my mom lives near so she usually takes me to what i need. she went to mexico however so i have no ride. we have another car but it doesn’t work that great. on monday, my daughter had a dentist appointment. i had told him when i scheduled it i will need the car those days. he didn’t care to pay attention though i guess because when i reminded him the day before he got pissed. so monday comes and he’s still complaining but says he’ll try the other car. apparently it had a flat tire so he took my car and i had to cancel. i told him our son had an appointment thursday so fix the the issue and he said he would. now he’s saying he didn’t because didn’t have time since he gets out late and he needs the car. but i’m like no i gave you 3 days. and he said well you did too could’ve canceled. like i already canceled one appointment and our son has not seen a pediatrician in about 4 months (busy pediatrician then had to switch) so i do not want to cancel it when it took me this long to get an appointment. he has a coworker nearby and i told him to carpool but he doesn’t want to. he said we can all wake up at 6 and take him (works half an hour away so would take an hour) but i don’t really want to inconvenience the kids like that. he told me to take an uber then but then id have 2 car seats and have to carry them with me at the appointment. i feel like because it’s my car, i should have it when i want. like yeah it sucks he’ll miss work and i know we need him to work since he pays rent but these past months he’s been asking me to pitch in money to pay it so like what is missing a day going to do? like am i in the wrong for wanting him to figure out a way to get to work so i can use the car to take our children to appointments? (daughter has speech therapy too)

edit to add: we’d probably lose money anyways since they tend to charge if you don’t give a 24 hour notice.