is an out of court private divorce settlement agreement between spouses valid and binding under MA state law

You stated that you didn't have assistence of counsel but did you actually get a divorce from the courts? If you did receive a divorce from the court (evidence by a Judgment of Divorce Nisi), then your separation agreement would've been approved by the court and if you want to make changes, you can bring a Complaint for Modification to the court that you got the divorce from.

If you never went to the court at all to obtain a divorce, then you are still legally married and a Separation Agreement is not valid and therefore not enforceable by the courts.

I agree; it is a contract that must be properly approved by the Court.

By now you understand that such an agreement should have been part of a divorce action, even a joint divorce action. You have the option, if your spouse agrees, to file a joint petition with the necessary documents, and then ask the court to approve these, and grant you a divorce.

Self-help in this instance was of little help to you both.

If you need assistance or have further questions, contact me.

Hi, It's not entirely clear from your question exactly what happened. Are you legally divorced? It is possible that the divorce agreement can be amended or modified, but it depends on the specific language in the divorce agreement. Was your Separation Agreement approved by a Judge in Probate Court? It seems like, if you have been paying the mortgage and paying all the housing costs for the past ten years, that you would be entitled to some sort of benefit from that, but it depends on what you got from your spouse when you got divorced. I wish there was an easy answer! You should have an attorney look at your Separation Agreement if you are concerned. I'd be happy to answer some questions. My contact information is on my website: www.sullivanandsweeney.com or massdrivinglaw.com

Good luck!