I would get yourself and your daughter to a women's shelter of some kind and find what resources they have available and "start over". You have good skills for getting a good job and if you want to keep supporting your daughter then you should first get a job and apartment or place to stay with just yourselves and then the two of you go on from there. But I would get out from under as many problems that aren't "yours" -- your daughter should be solving her own problems and if you have taken your mother to specialists and they found nothing wrong, she can go for awhile without your immediate worry/attention until you get yourself sorted and/or your brother can take the brunt and you'll "pay him back" later when you're in a better place.