Worst reason for a divorce I've ever heard. I am not sure if she will ever understand that. Basically you say you want to leave her because she gave you four kids. Needs to be avoided, really.
I agree on the Kegel training, brings a lot of added benefits. Surgery is also a possibility if she is willing to undergo it. Can't push too much here, it is her body afterall.
And until everything is working again, you need to work on your sex life. Talk about it, explore alternatives to fucking. Remember the days when you first met, you weren't straight in her pants either, but it still was romantic. You could also explore anal sex, which is a lot tighter.
