Is probate officially finished (is the estate closed) or are probate proceedings still ongoing?
I understand your extreme frustration at how you are being treated, but filing a complaint through the surrogate court is not the way to resolve this. The court employees who told you they would give you forms are violating ethical court procedure--they should have told you that they are not allowed to give legal advice and that you should consult with an attorney. Whether probate is finished or not, the surrogate court is NOT where you need to be, since the trust is handled/managed/and administered outside of and independently of the surrogate court. I strongly urge you to get your own trust attorney to ask if you need to file a civil suit against the trustee, so that your case can be defended and heard properly before a different court.
In my opinion--and this is sheer speculation--there could be problems (with these accounts) that have not yet been discovered. Is it possible that your brother and/or the estate attorney have somehow already gotten access to this money without your knowledge and may have stolen some or all of it and don't want you to find out? There is a reason that he does not want to give you what is rightfully yours, but no one yet seems to know what the reason is. Have you ever asked him verbally what is the reason that he has not begun the process to claim these funds and has he ever given you an answer?
This is NOT a do-it-yourself process if you want to have a favorable outcome!
Your trust attorney can have your brother brought into court to have him explain before the judge exactly why he has not made the distribution to you and to the other beneficiaries. His behavior might even be considered as a breach of fiduciary duty and he will face serious consequences for not properly performing his trustee duties in timely fashion.