I've done this in the past for years and it ain't fun.

Eventually you will burn out working 18 hr workdays, without breaks, vacations, family time, exercise and if you don't see much financial success at the end you will suffer a total disappointment with yourself and your life. That is if you are lucky enough to not run into health and financial issues before all this.

Besides the idea that working too hard automatically means success is just plain wrong. Money is not a linear function of effort. And real life success even in regular jobs depends on luck and things like office politics for the most part.

If anything working too hard will make your boss envious of you, and will work against your best interest. YMMV.