Diamond, for starters, to get the answer on whether your name is on the deed or not, you can contact the Plymouth County Registry of Deeds or perhaps look online yourself at http://plymouthdeeds.org/search-records-2.html
The online interface for the Plymouth County Registry of Deeds is not particularly friendly, but if you know approximately the date that the property was bought and the full name of your kids' father (as the grantee) you should be able to find the deed online and see if your name is on it too.
I don't know how close you are to foreclosure. When did payments start getting missed? When was the first notice received? You can look at http://www.hud.gov/foreclosure/index.cfm for some help in this area as well as housing assistance for you and your children. Get some people on your case as soon as possible!!
Best of luck.