FTFY I hope you're prepared to work at least five times harder than you did at your safe job, and for little to no guaranteed reward. Actually, if you're only giving yourself six months, make that ten times harder. I would say good luck, but considering around 90% of startups fail, work hard, be persistent and expect difficulty, seems more helpful to say. The success stories appearing on HN can give a skewed impression on how hard it is to succeed. Congratulations, though, for bucking a potential path of regrets.

Edit: A bit more advice is release early, and often. The trick is finding the balance between minimum viability and having enough value for traction. Iterating on an idea is almost always necessary, so be on the lookout for how that can help and possibly even save your endeavor. A six month deadline to succeed means you're really going to be up against it.