Thoughts on retiring - update!

Today I am telling my boss of my intention to retire at the end of January. I am going to be the FT caregiver to my 3 grandchildren when my daughter goes back to work after her maternity leave. The baby girl will be 3 months then and the other kids are 4 (in preschool) and 8 (3rd grade).
I fully understand this is the definition of a first world problem. I have been payroll and benefits admin for a PA school district for 14 years. At 62 I qualify for “full retirement” in PA public schools. Plus here in PA, public employees qualify for full SS as both sides contribute.
My husband (age 60) has a good secure job; of course no job is really secure these days but he’s been there 15+ years, it’s a stable company that treats their people well. I will go on their insurance for the next 3 years. It’s a good Blue Cross PPO, comparable to the Aetna I have now but more expensive for the employee. Not a high-deductible plan (thank God).
The only debt we have is the mortgage. Paid off my car loan and the rest of the Parent Plus loans we took for our son. No credit card balances. We can afford to live on his pay and my pension. If I have to I could start my SS too but would rather wait on that if we can.
I like my job and I’m good at it, but I don’t define myself by my career. I play in and I’m business manager (volunteer) for a community concert band. I’m very active at my church. None of those things will change.
But I’m terrified to do this. I’ve been putting off telling my boss for a while now. I told her I would give her lots of notice when I decided to retire. At my last review she basically begged me not to retire but she knows how old I am and that this day is coming sooner or later.
Am I an idiot for giving up a good job with great benefits, a short commute, that I can pretty much do in my sleep? Am I an idiot for trusting my husband’s employer to keep us afloat for the next few years?
But...I promised my daughter. And I love my grandkids more than anything in the world. I’m healthy. I don’t want the baby going to daycare and getting sick all the time like my kids did. Kid #3 is their last so I can really retire in 5 or 6 years. I was never a SAHM with my kids. Here’s my chance to be a SAHG. I’ve been doing the “business world” thing for almost 40 years. I’m looking forward to going to “work” in jeans and a T-shirt and no makeup.
Yes this is a first world problem. Tell me I’m doing the right thing.

***update****
I just told my boss. I did it. She was very nice and understanding. I have a lot to do before I’m gone. So relieved I got that over with.