I was in a similar situation a few years back. I had the opportunity to take early retirement and a generous redundancy package at age 51. I spent roughly £25 k on the CPL and FI rating and I now work 4 days per week at a local school. I am fortunate in that I can live on my pension. My earnings as an instructor are more or less offset by my expenses, so my net additional income is zero.
I don't regret the decision at all, but as others have said, don't do it if you need the money. The job itself is very satisfying but can be frustrating at times, especially on the no-fly days.