Permanently exhausted... trying to do too much, or just exhausted by life?

Hello

I'm finding, at 46, that I have significantly less capacity/energy than I used to. I've been self employed for 6 years (which is just a different type of stress but at least I have more control over when & where I work).  This is probably a 'how long is a piece of string' question but how can I tell if I'm "trying to do too much", or I'm excessively exhausted trying to do very little.  I'm struggling to get a read on it.  Chatting with other non-Aspies I trust it doesn't feel like I'm achieving a great deal considering how exhausted I am.  I've not been formally diagnosed as Aspergers, but feel it is a dead cert given everything I've read, and I have no other indication or reason to believe I'm not healthy so I'm reluctant to go to the doctors.  I have a healthy diet and get decent sleep etc.

Do you find you get more tired than you expect from doing different activities? I know that some things (socialising, noisy environments) wear me out, and seemingly more strenuous activities (hillwalking) energise me so it's hard to get a sense of how to manage my energy levels.

Any thoughts on this are welcome, sorry the question is not very clear.

Daisy