G.:
I personally wouldn't throw in the towel and uproot my children without getting to the bottom/root of the problem. No marriage is perfect - heck my parents have been married for 54 years and there are times they look at each other and throw their hands up in the air...
I can't speak for him, but he sounds like he's angry because he feels the marriage disintegrating as well...sounds like you both need to learn how to communicate with each other again...divorcing and leaving isn't going to change anything but the location...you are still going to have to parent together. So before you leave - go to counseling and learn how to communicate with each other.
I know I am not the same person my husband married 14 years ago nor is he the same man I married, life happens, things change you....maybe he's angry because he doesn't KNOW how to tell you how he's feeling or maybe he wants to tell you but you have your defenses up so he doesn't feel he can talk to you...I don't know...I do know that it's give and take and you need to communicate with him - do NOT accuse him - talk to him the way you want to talked to - honey - I am feeling anger from you- can you tell me what's going on - or however you want to say it - if you accuse him of always being angry - it will not be a productive conversation...
You might have to rearrange your priorities...maybe he doesn't feel like he is a priority in your life anymore - that it's all about the kids....I know as a SAHM that the kids can consume you - but the marriage always needs to be first....the kids grow up and move away....the marriage is supposed to stay...
Sounds like you are angry too. In no way should you pretend your marriage is perfect...as I said - NONE ARE! It's what works for the couple...get counseling for both of you...you might be surprised at what you learn!!
GOOD LUCK!!