Sell the restaurant, especially if it isn't making you money. Use the cash to finish training.
There are loans out there for flight training but if you can do it without loans then even better.
Have you considered joining the military or national guard (not as a pilot). You can qualify for the GI Bill which pays for flight training. If the military isn't for you, then I don't recommend this option but if you think 4 years is reasonable then financially you can make it work.