I went back, but only took 2.5 years out. I left due to horrendous work-place bullying and at the time I left, I didn't ever want to go back into teaching, BUT, after doing an awful lot of research, teaching had far more pros, so I decided to suck it up.
Like you I felt I was too old to re-train (same age as you), I know people will say "you can do what you want at any age, start a new career at any age", BUT, the return on the investment gets less the older you get. Everything remotely interesting that I looked at required years of training eg. another degree and/or starting at the bottom of the pay ladder, i.e. back on about 22K. I just wanted to get a job and earn money. TBH there wasn't anything else that really grabbed me either. If I'd had a burning passion to do something different, then I would probably would have pursued that.
Other cons were: I was looking at office-based jobs, so I wouldn't have been able to leave until 5pm, and my DDs do loads of after school activities that mean I need to leave work earlier (which I can do in teaching, the downside being having to take the work home). Getting childcare in the school holidays would have been a ball-ache.
To get back into teaching, I did some supply first, decided I hated supply, especially being controlled by the agencies. So got a temp, maternity, part-time cover job in a school directly, and it was at that point that I landed on my feet. The school is lovely, management are so supportive, and I'm still working there now.
The key is to find the right school.
I wouldn't say I enjoy it, but the money is good, meaning I can live the lifestyle I want (a lot of travelling/holidays!), and it's definitely not boring. Workloads were very high when I first started back, like being an NQT again. I couldn't have worked full-time when I first started back (I am now).
With private schools, it depends where you live - I would really suit working in a private school, but there are hardly any of them round here. I've managed to get to interview a few times, but never got a job. They always seem to want someone who is offering to coach a sports team, and I'm not at all sporty.