@sallymartin , kids can have an argument, but adults take it to a whole new level!
I feel for you, having to go through all this and having MS. Life can be brutal. but in these trying times you do need to try and manage your stress levels.
How old are your two boys? Have they stated a preference or are they not old enough to understand the gravity of the question.
The law does favour the Mother, unless your suitability for that role can be called into question. “Mud slinging” will occur, but it’s whether it can be proved that the mud sticks.
In the past, Fathers put the food on the table and Mothers made the home. These days, Mothers also put food on the table, but can Fathers make the home – only sometimes!