OP, all of what PP said.
Try to reframe: you are making a strong and brave decision. I was in a marriage with similar soul-crushing dynamics, and I stayed until my kids were 11. I should have left much sooner.
I heard this -
http://www.npr.org/2017/05/02/526514168/why-social-media-isnt-always-very-social - the other day. It may or may not pertain to your situation, but (among other things) it was a reminder that you really never know what's going on in other people's lives.
Be thoughtful and deliberate and true to yourself given your circumstances. Keep the shame at bay the best you can.