There must be something that you want to do. 40 isn't that old. Totally change your profession, travel, etc. As others have pointed out you need to move on f

There must be something that you want to do. 40 isn't that old. Totally change your profession, travel, etc. As others have pointed out you need to move on from the crippling focus on your age and lost time. If you continue to focus on that, you will only lose MORE time. Seriously, drop everything, re-train, and start pursuing life on your terms. I'm not saying it will be easy but sometimes having a purpose and struggling can be more rewarding then wallowing in comfort.