Longhaul gets tedious as you get older, and as you get older the sleep gets worse! I found although I was flying the worlds best plane (747-400), I wasn't enjoying the flying anymore. I would recommend if you do fancy flying on, do something different. I've gone from worldwide longhaul widebody to medium haul narrow body. Flying a 737 around Europe to holiday destinations, down to Africa, even across to Canada. Totally different, and interesting and fun because of its novelty value, which will take years to wear off. It's variety that makes it interesting.
You really need to get out of it for 6 months to know if you want to come back. If you don't miss it, well great- enjoy your retirement! But only you will know what the voices in your head say to you. Yes, I have 'voices' in my head! They're saying 'get your ass out there and get earning! Retirement lasts a LONG time (hopefully), and there's not much use deciding in 5 years that you'd like to fly jet airliners again!' You could be retired 30 years. Time enough for golf and sailing and gardening another time. Use your constructive years while you can (unless you really want out).