First off, my condolences to you for having to deal with this at a time when family should be coming together.
Misuse of monies of the elderly constitutes abuse.
If you are not familiar with 211, give that phone number a try. They are information for Social Services and may be able to put you in touch with pro bono (sp) lawyers in your area.
You may also want to reach out to any Elder Abuse organizations. Here is a link to the National Elder Abuse Hotline, www.ncea.aoa.gov/. Their front page has a link to state hotlines.
On a personal note, we in the GLBT community have been facing this type of behavior from our 'christain' family members for as long as I can remember. I am 52. My mother and I came out at the same time in the early 1980's. What your family/ brother is doing to you is NOT your fault and no way reflects upon you! My gay brother put my homophobic sister and her husband in place to care of our mother. She was forced to sit and listen to fox news. They took her bed and when she asked for it back, they refused and told family that mom was gone and they could do anything they wanted. They lasted less then a year in the house when they walked out one Friday evening and left mom in the care of another sister, the one they claimed had been abusing my mother and her money. This is only a very little sample of the things my siblings did to my mother and those of us that challenged them. For my family, it was the culmination of generations of abuse and adiction showing itself
We went to court for guardianship and won after a year long court battle. We buried my mom in 2014, after 4 years of laughter and tears as we lived together.
Good luck and try not to take what they do personally.... I know easier typed then done. It took it's toll on me and my good sisters.
Hope the hotline info helps.....
Peace,
Scruffy