Open Question: Should I file an EEOC claim against my previous employer?

I am a 32 year old black female and I recently resigned from my employer and stated in the notice I was resigning under "Duress" due to harrassment. I had been in an ongoing situation with my white older male coworker who had lied on me to management and said I had harrassed his wife and was approaching my coworkers stating things I said that I didn't say. The guy had been at the company much longer than I (I had worked there for 2 years and he for 5 years) and was throwing his weight around. It got so bad with several different people approaching me daily and with this guy humiliating me in front of customers (he was one of the front end supervisors) that I had started to emailing HR and the store manager asking for someone to intervene. They supposedly did an investigation but never got back to me on anything and simply stated it was closed. I also had several customers notice the way I was demeaned and humiliated at my register and they even went to management about the guy. Finally, I couldn't take it anymore and put in my two week notice in which I stated I was resigning under "duress" due to the ongoing harrassment and that management had failed to stop it. I also noted it was causing me to become sick. Right after the notice, I started having anxiety attacks and had to go to the emergency room. The Emergency room doctor prescribed me Zoloft and Klonopin and put me on emergency stress leave for 5 days. When I called the company the store manager was very rude and stated he would not fax the leave of absence form to me and that I had no choice but to come into the store on my sick time and pick it up from him directly. When I came in he called another manager in the office and spoke with me and finally asked me to walk out. He then called me back into the office and stated he was making my two week notice effective immediately. Then the Asst. Store manager typed up the Termination notice and stated on it that it was a "voluntary" termination due to "Career Change" and that I was rehirable and asked me to sign it. I refused and she put "refused to sign". Then on the way out the store manager looked at me so funny and stated "If I ever needed a reference he would give me one". I thought how strange for them to end my employment that way. You all know my employer as im sure many of you shop there. Its the largest employer in America right now and is always in the news for discrimination types of cases. Well, I have filed for unemployment and I have my numerous emails to Management and HR detailing the harrassment. I have over 20 emails to the higher ups. I want to get my unemployment but I believe the company will fight it especially when they listed on my notice "voluntary termination". Because it was clearly a hostile work environment do you think I have a chance to succeed. Especially given the fact that I started suffering panic attacks from the stress which is documented? Im in Texas by the way. Also should I file a claim with the EEOC?