problem with a person that bought a house from me.

I sold a house 16 yrs ago to a friend of mine. she was married and had a daughter who was getting social security from her dead father. she used the daughters money to make the monthly payments.
she had to rent the property for a yr until she could get a mtg.
soon after that she went into rehab for alcohol abuse and her husband got the atty to close on the house. when I went to the closing the lawyer had taken every penny she had paid for rent and applied it to the mtg as a down payment without my knowledge. to say I was mad is putting it mildly but at that time I had no other buyers for the place and signed the mtg agreement.
Now 16 yrs later I got a letter from the guy saying my name was listed in the court house on his mtg and he wanted it removed so he could remortgage the house.
I never put the mtg info in the court house. I told hte man to get the lawyer that took all the rent money and applied it as a down payment without my permission to take it out of the court house since he was the one that msut have recorded it in the court house. I was told that I can be sued if I don't release the mtg. I had told him to send me 250 and I would search the bank records and the income tax records to make sure everything was paid for and he refused. Now I have a lawyer threatening to sue me.
the guy and my used to be friend have long divorced. this guy told his lawyer he made monthly payments and didn't miss a payment. actually the man never made a payment his stepdaughter paid with her fathers social security money. I am not sure the bal was ever paid to me. I remarried soon after that and went on with my life.
since this guy took advantage of me the first time around I am afraid to sign anything without checking more into it..
what are my options?

no one has replied to my problem yet.
after 16 yrs I was contacted to remove a mortgage lien from the court house.
I asked for 250 to hire an attorney to make sure the mortgage was paid for and then give me advice on signing the release from the court house.
since he took all the rent money and applied it to the down payment on the house with out asking me or letting me know prior to the closing I am hesitant about signing anything for him. He is refusing to give me the 250 for an attorneys advice and I am not sure I could hire an atty for 250.00.
I don't want to sign anything without a lawyer looking at the paperwork at the court house.
the man is threatening to sue me if I don't sign off the mortagage.
I have had a series of mini strokes and I am almost 70 yrs old.
I don't recall things the way I used to and I am a nervous wreck with this thing.
please advise..

you don't need a lawyer. the man must show written proof of paying you. have someone go to courthouse and check to see if any documents were filed during the time frame (when you get proof of payment).