Am I right to break up with my optometrist because of this?

Dentist and optometrist both do this. We pick a time… knowing that we can reschedule later. But for instance, 6 months from now my son will still need an after school appointment or a Saturday. My husband will need Saturday, and I will book at the same time as one of them, knowing I can change mine if things change for me. Currently husband and I are out of synch with our glasses years, but that is ok too. I take my son every year for eye checkup.

I think so. An annual eye exam is a routine thing. They gave you plenty of lead time, you cancelled well in advance so they could give the time slot to someone else.

Were you happy with the glasses and the service otherwise? If so, go back to them.