Jo.....you have a lot of weight on your shoulders....and, too much to carry alone....without knowing all the details.....I still say that you need to get support and help...as much as you can gather around ....
If he has a 401k...I assume that you still have health insurance?
In my opinion...stick close to your ophthalmologist, first of all....and seek out a therapist who is experienced with dealing with anxiety disorders...as they will be the best to help you with the panic attacks...
And, an advisor to help you with fading the financial realities of your future...(this can be from a variety of sources...depending on the specifics)
The more help you get, the better.....
It is good that you could come here to vent...that is good, also....
Keep it up....