As bad as you may want to quit your job, the only thing I have to offer is that you need to keep in mind the pros and cons of not having your full time job.
1) Insurance if you have it at your current employer
2) Steady income during the winter months or slow times
3) Retirement or 401 k
4) Social Security (not that i believe we will even have it by then but who knows)
Ultimately, if you feel some of the things i listed is not an issue, then by all means move forward into the next chapter of your life by doing the new business