Glad you made yourself visible here and it'll help you to know a lot of us are experiencing many of your feelings and frustrations. Care-giving is a strong burn-out profession and I wish they offered more trainings on that very topic.
And yes, this time of year is one of the worst for these feelings. It's so very important to make taking care of yourself and your own family, your first priority. Make sure you visit your dr., dentist, whoever else is on your list of health providers, regularly. That was a big mistake of mine.
Then schedule time for just you, doing things you love and can escape real life with. Schedule time for your S/O and you, and finally schedule time for you with your own children.
Because this is such a personalized profession, involving ourselves with children and other families, we tend to give, give, give of ourselves before we realize we've given our all and have nothing left.
I've gone through ups and down over my entire childcare career, swearing I was going to quit, but then that next month I was re-motivated either by seasonal changes or fun workshops I attended, changing up my dc or buying new equipment, tightening up my contract, etc.
Now I am in the final throes of offering daycare, haven't given anybody notice yet because I'm confused about a final date and not sure if I simply want to get out from under the state's thumb and only take the legal amount or retire altogether.
I do remember the most difficult years were when I was a mom of 3, still living with my dh, and most of the household chores were upon my shoulders. That was hard. I completely lost myself in that time period. Everybody always needed something and it was me they expected it from.
Perhaps you can delegate some of those types of responsibilities to someone else in your household? Can you afford to have a cleaning service come in once a month? Plan easy quick menus. Share babysitting services with a friend or neighbor to get out of the house more? Invite a friend over for coffee?
You said you do some Meet-up groups, good for you!! I wonder if there would be any way you could start one, involving motherhood and challenges or providers who are maxed out. Is there a good provider network you could join to gain insight into dealing with these feelings? Any fun workshops being offered? Can you take some long weekends? (I hope you charge by enrollment and not based on attendance? I learned that here because I never took time off, felt I couldn't afford it so that made it even worse). Find support whether IRL or online because nothing can help like other people knowing what you're going through.
There are so many ways to help alleviate burn-out. But if you've tried everything and it's gone on for far too long, maybe it's time to step back and re-evaluate where you want to go from here.
Good luck and hope something changes soon for you!!!