SSDI or SSI are federal disability benefits. For SSDI you must have a substantial work history, have contributed to SS over the years (some professions like teachers often do not as they contribute into a teacher's retirement and disability plan). Your first step should be to check out www.ssa.gov - there they can answer some of yoru questions by the information and FAQ they provide. Also, a few months before your birthday each year you should receive a mailing from SS that details out your earning history, what you can project for possible SS retirement amount in the future, and what you'd be eligible for under SS disability if you became disabled today. If you don't have that document you may be able to get one via the SS website or your local SS office.
Your state, MA, doesn't offer any type of state disability beneifts. The only states that do are NY, NJ, RI, CA, HI and PR.
Are you currently working? If so your employer may offer STD or LTD (short term or long term disability). I'm fortunate that my employer offers both and I had STD for 26 weeks and then my LTD started in Noveraber. I may have to apply for SSDI, the insurance company will mandate it, but I'm putting it off in case I'm able to return to work.
I highly recommend seeking out a SS attorney to help you down the road. SS application process can be long and frustrating. If you do chose an attorney - be sure their primary practice is disability law.