Son,

You have looked into many avenues in search of ways to help your mother.
You have received much good advice and support from this forum. You have spoken with your mother's doctors.

Have you been in touch with any clergy? Every hospital has a chaplain. Particularly if your mother is receiving care at such a major facility the chaplains are experienced with the heartbreaking situation you are experiencing. Although she is not currently hospitalized there they should be able to help you and can even steer you to someone of a particular faith. Have you spoken with a clergy person who is familiar with your mother and or yourself? Every faith has specific prayers for troubled times. Be as agressive with this as you have been in the other paths you have been exploring.