terminating alimony in MA

[cocoa]

Hi All,
I've been divorced now for 1 year, separated for 3 years.  How do I revisit the alimony and other divorce stipulations?  I had a real loser attorney and I agreed and wanted to at the time, to support my ex wife.  The problem is, there is no ending date for terminating spousal support!  Since the divorce, things have changed.  First of all, is my health.  I have multiple sclerosis, and while I did have it one year ago, it is worse now.  I have only my disability income to support me.  Also, my ex is supposed to get more money when the youngest (who is 20 years old) is finished with college.  He is currently not in college, just taking 1 or 2 courses, non-matriculated.  Oh, and one more thing to complicate matters.  I am now living in Rhode Island and my ex is living in Maine.  Where would we even go to court if we were divorced in MA?
Thanks for any help!
Fran