I feel for you and your family. I have gotten to know you guys, somewhat, over the past few months for your blog. I have 2 family members at different points on the spectrum, which got me starting to read your blog in the first place.
Oddly enough, however, so many of the problems you're going through, especially with Gavin and his regression, have hit so close to home with a totally different family member: my dad.
We lost him to Alzheimer's. I am not quite sure when, it is hard to pin down. But you mentioned a switch going off with Gavin when he was 3, and this was the same with my dad, only his was a dimmer switch. But it went all the way down. I watched him regress to an age capability of two. Probably less, because he couldn't use utensils, the bathroom, or dress himself. Eventually he lost most of his speech, too.
But like Gavin, out of the blue, when you least expect it, a spark would flash and suddenly for a moment my dad was my dad again. And just as fast, the spark was gone. I did not even consider him my dad mostly anymore. Just this horrible "thing" called Alzheimer's. And. I HATED Alzheimer's. I am not a bad daughter. I loved HIM. Not the Alzheimer's.
I understand how you feel about Gavin, and then having your other two also have similar problems – well I don't know how I would survive if it were me. You and Lizze are very very strong people. And very caring and loving parents. You go way over and above what could be rationally expected to do. And yet you do it. Every single day.
I know I do not live close, or I would offer to physically come over to help in any way that you would have me. If you think of any possible way I could help, I would be glad to. Except financially. Unfortunately our 3 credit cards got maxxed out and they took them away from us. But if there is anything else that you can think of….. well, you have a stranger in NY who cares. Be well and stay strong!