eyjafjallajokull_'s journey

I recently quit my contract position at an engineering firm, and now I'm second-guessing my decision. While the work itself was fine, my boss created a toxic environment by constantly hurling insults and getting personal. It became unbearable, and I dreaded going to work every day. I’m worried that I might not be eligible for unemployment since I technically quit, and my resume is starting to look concerning with four jobs in three years. One was for about a year until the owner retired, and the others were contract roles. I fear it might come off as job hopping. I'm trying to figure out how to explain my situation to potential employers and how to present my experience in a way that doesn't raise red flags.