I am trying to determine the strength of potential litigation against an employer with hopes of securing my severance package.

After a lengthy degredation of duties and responsibilities, and numerous requests for remedy or return to originally hired duties, along with no salary payments for 2 months, i resigned because i could no longer function mentally, emotionally or financially.

The company encouraged my resignation with the encouragement of a significant departure package. The CEO represented this package (supposedly) to the board. I was infomred by the CEO that the board did not approve any of the items on that package, but accepted and encouraged my effective date.

I belive that this is a clear case of Constructive Termination, but should i find a lawyer or use provisions within the California Employment Law mechanisum to begin the process

It isn't constructive discharge from what you have described, but if they failed to pay you for two months, it is a wage and hour claim. You could file one with the DLSE.

While you can certainly mention filing a claim if they do not pay you the wages they owe you, I would not try to use this as a bargaining chip to get severance which is not legally owed. That would be extortion and you do not want to go there.

It is legal for them to change your duties and responsibilities as they see fit, just as it is your right to vote with your feet and seek other employment if you do not like those terms.

The general rule is that the employer is going to take you more seriously if you have an attorney. Most do free or low cost initial consultations. I would at least talk to a few lawyers and get a feel for whether you should hire one.