Should I Resign From This Job? Please Help Me

I have been working for a company for 35k per month for 12 months no increment. I have been promoted from one position to another without a payrise.

Late May this year my salary was increased to 50k with a whole lots of tasks, I work Monday to Sunday, 7.am to 7 pm some times down to 9 pm.
1st week of June a similar company based on recommendations invited me for an interview, they offer to pay me 120k, which I insisted on 150k, finally, they agree to pay but when we went to the business place.
It is a little beginning business that I have to grow from scratch in an isolated area.
I began to reason if I opt out of my present job and venture into this, how long will this payment last, if the business folds up, where will I start from?
In my present job, it might take another 12 months before another increment but I can work there as long as I may wish to work cos it has job security.

Please Advise Me Am Confused And I Have Family With Kids.