You share a very complicated and clearly emotion-filled set of facts. It sounds like you may be the defendant in a lawsuit filed by your ex because you mention a lis pendens. Plus, you say you've been wronged by this person and believe you may have valid legal claims against him, as well.
It's clear that you would benefit from retaining an attorney, even though you write "I really cannot afford to pay much upfront to an attorney." Your best bet is to go ahead and call a few experienced litigation attorneys near you for a free initial consultation. They'll ask you for the important facts and after you have a chance to explain the situation more fully they will let you know on what terms they might be willing to take your case. They'll also give you a sense of how urgently they believe you need to retain counsel. At that point, you'll have a lot more information about where you stand on which to base your decision as to how to proceed.
This is intended for general informational purposes only and does not constitute legal advice or create an attorney-client relationship.
I agree with my colleague's answer. Since you are a trustee, you have the right and duty to know what is going on with the property and to protect the interests of the beneficiaries, your children. You should try to get a consultation with an attorney to discuss your options because this does sound quite complex, and you may be able to find an attorney who will take your case on a contingency fee basis, meaning that you pay little if anything up front. If you feel like this person is a danger to you or your children, you should contact the police. Best of luck.
Please be sure to mark if you find the answer "helpful" or a "best" answer. (It lets us know how we are doing.) Attorney Kremer is licensed to practice in Massachusetts. Please visit her Avvo profile for contact information. In accordance with Avvo guidelines, the following disclaimer applies to all responses given in this forum: The above is NOT legal advice, and is NOT intended to be legal advice. No Attorney-Client relationship is created through the above answer.