u/Lpithon

I've been working full time for a person, and since he found out that I have a second job on Upwork, even though I explained to him that it's only 10 hours a week and it's the double of the price that he's offering me, he said he didn't like that, and it sounded very toxic. So I wanted to quit because the way that he treated me, but I am afraid because I've seen a comment on his profile just yesterday that he threatened to give a bad review to a person that wanted to quit as well. What would you guys do in this position?