Was I discrimated because I requested Health Insurance?

I was terminated today for unknown reasons; I worked as a Director of HR for a family owed Footwear Company in NYC for almost 1 1/2 years as a permanent P/T employee working 24 hrs per wk.
I was told at the beginning of employment that I would not be eligible for Group Health Ins. as I needed to work the max of 30 hrs/wk. In 2008, the company did some layoffs and reduced one FT EE to PT, working 24 hr/wk, upon benefit renewal, we amended the plan documents for eligibility requirement at 24hr per wk, we have two employees that are currently working under 30 hours and both are receiving health benefits. When I ask about getting health insurance, I was told yes but I would have to pay 50% of the premiums while all other employees paid the 48-52 per pay check, 50% of the premium would cost me 150 per pay check.
Upon termination, I received a severance letter, stating the company would pay me 3 weeks’ severance only if I sign the agreement, by signing the agreement, I agree to voluntarily release and forever discharge the company from all actions and claims connected with my employment or it's termination, including FMLA, ADA, NYS Human Rights Law, FLSA, etc., I'm not sure I want to sign this. This company, like many others is getting away with discriminatory actions.
I work on an hourly basis, never would they pay me for any OT or extra time put into the company, my direct supervisor, COO signs off on my timesheet with more than 24 hours per week but I only get paid for the 24hrs. I have already spoken to the US Dept. of Labor and I was told that I am entitled to Health ins based on the information provided but the one thing they couldn't do was protect me from retaliation.
What do you suggest I do?