Yes, IT security is the current demand and quick way to a higher paying step of a career. But... it is just a 'wage slave step' one that may lead you into a business.
Do you have a strong idea of where you want to be? (I love Power distribution and live in the midst of Bonneville Power distribution, grew up in Bureau of Reclamation area, and consult for wind and alternative energy)
Run down to your local worksource BEFORE you quit and note the people lurking for work. Pretty sad with a wide age and skill range. Take some of the free aptitude tests and plug your results in to a career path. Go talk to those who have done it (there are plenty who switch many times in their career, and are very happy and successful doing so).
For finance, I would look into taking CFA (Charter Financial Analyst) but that is not a sure thing and takes a minimum of 3 yrs. Many finance positions start and ONLY hire Accountant majors, just to prove they are capable of diligence and rigor. One of my kids is a CFO and another a COO, but no silver linings, yet (high dollar Buy outs). Building the companies, staying competitive, keeping an eye out for 'next steps'.
You certainly have the right stuff, so find your niche. That takes exploring and possibly a lot of No's. Do this soon. age 50 may be too late for a significant career change outside your expertise.
There can be a lot of dough and fun in fields leveraging your expertise.
While I was an ME, I steered clear of the office and factory by doing international procurment (now called sourcing). My technical background was essential. The staff on the business end had a lot more fun. They had to only deliver financial results. We had to deliver tangible results, moment by moment, day by day (No product = no sales!
). I enjoyed working with technical nationals in other countries, but I disliked working in an office, so I found a way OUT.