Hire an attorney ASAP and file a Petition for an accounting. If not required by the terms of the Trust, you should be able to obtain an accounting pursuant to state law. Depending on the facts, you may be able to bring an action for breach of fiduciary duties, etc. I assume the trustee is an individual as an institutional trustee would not deny info to beneficiaries.
Get a lawyer ASAP. I handle a significant amount of trust litigation and the sooner you act the better.
Mr. Post is licensed to practice law in KS and MO. The response herein is not legal advice and does not create an attorney/ client relationship. The response is in the form of legal education and is intended to provide general information about the matter within the question. Oftentimes the question does not include significant and important facts and timelines that if known could significantly change the reply unsuitable. Mr. Post strongly advises the questioner to confer with an attorney in their state in order to ensure proper advice is received.