75k really is about 6 months of expenses and costs. Biggest mistake people fail is not having enough runway. If your living in the midwest and your monthly costs are $3-$4k a month (remember you need health insurance) then you'll have 2-4 months additional runway. Best recommendation, take some time away from work, but get serious about having a schedule and having a date/metric about when you must get another job. Another big thing I've seen is lack of execution, the technology is the easy part, running the business consistently is hard. Use freshbooks.