Your brother likely feels that as he took care of her, not he deserves everything. Fortunately for you that is NOT what the trust says.
Your brother is acting outrageously and in serious breach of his duties and could be compelled to act in accordance with the law and trust, or removed as a trustee for his gross abuse.
As for where you should go, I suggest that you contact an estates lawyer in Sacramento (if that's where he is).
This is intended as general information only, NOT legal advice. You are not my client and I have no obligation of any kind to you. To retain a lawyer I suggest you go to www.AttorneyPages.com.