Never Received Salary Promised/Company Sold

I went to work for a new small business company in NYS as Director of Technical Services.I was promised that the first 3 months that I would receive my monthly pay equivalent as stock in the company and was put on regular pay on month #4. I was promised a paycheck starting 15th of month #4 but the main investors held up money. The beginning of the 5th month I was put on company sponsored health insurance but only was given another promise for a paycheck on the 15th of the 5th month. The company sold the assests of the plant to a larger company at a substantial profit and promised to make me whole on wages. I continued to have health insurance coverage thru the 6th month and collected unemployment against this company for June and July. I have repeatedly requested my wages and my stock share. I have been told I will receive half my wages if I sign a Severance agreement first if I fail to sign I will get nothing. What are my options? I have supporting documentation of an employment contract and a letter from the company attorney stating I was a full time employee. I also have copies of all the daily sign-in sheets(Jan-May)that were required to gain entry to the facility. The company letter of incorporation and several letters from the vice-president and co-founder supporting all claims.The company that purchased the assets hired me full time to coordinate the start-up of the equipment purchased.