It's very simple, but you have to do the work yourself. For anyone else reading, this is the stuff you do long before you retire. But, for the OP, it means carve our tomorrow and get a calculator (it's all easy math, fortunately):
How much do you need each month? Shredded statements? Go to the bank, get the last two years reprinted. Add them up. That's your starting point. The good, the bad, the ugly, that's two years of expenses, voila. Good enough to say what you'll need for the next two, if you add 10-20% for lumpy expenses. You need $xthousand per month. Taxes, Mortgage, food, gas, movies, garden, repairs, utilities, shopping, hobbies whatever it is. Don't try to subtract (don't need this or that anymore) just go with that as a starting baseline.
How long till 59.5? If it's 4 years, double your first answer - that's how much you need to carry yourself. Subtract your pension income and savings, and then you'll know if you have a gap or you don't.
Do these two exercises, and you'll have your answer. If you are golden, good. If you are not, you'll know how much extra you need to make each year, and whether that's done with a job or some investment changes is a question for later. Or whether some of those expenses can truly be eliminated. But that's phase 2.
Phase 1 is your homework now.
