Disabled after losing benefits?

I began receiving SSD in 2007 at the age of 21 due to mental health issues. Last year I was found to no longer be disabled and lost the benefits. In September I began work at a haunted house (Until Nov 1) and the first day I had a migraine. In October I started work at a grocery store and the migraines and other headaches escalated over the months. I've had to quit my job and am seeing a Dr. (I have another illness as well, PMDD, severe pms) This past year I made under the SGA amount, except October I may have been over.

I am going to apply for disability but don't know where to begin. I'm thinking I need a lawyer first. It's unfortunate I have two very "invisible" illnesses that are easy to brush off. Curious if anyone thinks this will be easy or hard to prove, and would it be an immediate reinstatement or starting over? To think I was on disability for one thing and it ended up controlling another illness but I had no idea until I returned to work.