Can a Life Estate be revoked?

Put my son on a LE four years ago with his verbal agreement that I could sell when the upkeep became too difficult (rural 22 acres, fencing, having farm chores,etc). When it became clear that I could not keep it up without hiring help, I decided to sell and move closer to my granddaughter. My son has decided he will not sign..sending me texts and emails demanding money and calling me names. He also emails my siblings and granddaughter telling them He planned to sign but now feels he is "owed" the property and that I am evil. His emails are erratic saying he will sign, then not. I think he has lost his mind. As all my assets are in the property, am I out of all I worked for all my life? I already know the lawyer who wrote up the LE screwed me and did not perform due diligence but ...small town and the lawyer was the county attorney, so no other lawyer will touch it.