I read this wondering if the problem is physical or mental. Sometimes, physical problems are mis-diagnosed as mental, either by the doctor or due to ignorance of the medical community.
I worry constantly about the same thing with my wife, knowing that it will happen. Hers is due to diabetes:
Your Partner has Diabetes, YOUR Life just Changed
As important to know as CPR. You are not diabetic but know someone who is — your life may also change