When can I quit my job?

I currently have a stressful job that pays about $100,000 a year. I want to quit my job and get an easier one that pays less. I am 30 years old. I have a paid off townhouse. I have about $200,000 in stocks, most of which are in retirement accounts. I have about $50,000 in stocks/bonds in a brokerage account which I have access to. I earn over $100 a month in passive income in the brokerage account. Most of my expenses are property taxes. My monthly expenses are about $2,000. My question: How much monthly passive income should I achieve in my brokerage account before stepping down? I am currently single and have no kids. I imagine that my expensive might go up in the future.