Welcoming 2010 with memory problems

Can't blame it on too much holiday cheer - no alcohol for quite a while. I refuse to go to "oh no, a brain tumor" - other biological things are in play that act on memory. Such as:
1. My thyroid has been low, it turns out, so my primary care doc is working to get me level again. Thyroid disease acts on memory.
2. Stress acts on memory, and we have been experiencing some run-of-the-mill type of stress that follows both adult kids living at home and all of us held captive by sub-zero temps.
3. I am of a certain age - pushing 50 doesn't mean I am elderly (unless I was born near the turn of the 20th century), but the brain has gone through a lot.
4. Disturbed sleep patterns act on memory - due to any of the above, my sleep has been poor over the past couple of months.
I feel like I am in a constant state of deja vu, feeling that I have already done something that sounds like a good thing to do or something that I need to get done by a certain time (bill paying, sending birthday cards, emailing thanks to someone for the difference they have made in my life), when I am probably experiencing the echo of the original thought. To cope, I have lists (and I am NOT a list person), with dates/times/other clues showing that I have done the deed that I need to do. The alternatives are that either the thing doesn't get done, since my swiss cheese brain thinks I have already done it (pretty bad that I can't trust my brain these days), or I do it twice (making my semi-duplicate initial messages to an old friend Facebook seem like a stalker, or resulting in co-workers getting multiple happy birthday wishes, which is happening to those born in January). Let's just say that I won't be applying for Jeopardy any time soon. And I rein in any comments or offering of facts when in groups - not sure if a) it has been said already, and/or b)I have the correct fact in hand. Since my professional day is spent verifying facts, my job performance is doing ok (as long as I follow the lists), but I couldn't play Trivial Pursuit right now if a set of synthetic taste-buds was the prize. The thing I noticed today was that I couldn't record entire telephone numbers - had to look up and record 18 of them for a handout I created. I could go back and forth and type in the number on the handout 3 or 4 digits at a time - not the entire 10 in one whack. (Cut and paste was not an option this time-just short term memory.)
The spouse suffers in this, too. I ask him multiple times about something coming up or what he might want for lunch, say, and he gets to thinking that I am a huge nag. Or I don't communicate with him at all about something that blows up later. Lucky for me, he is pretty patient. As for Lucky the dog, during this cold weather I stand at the open door to make sure I get him back inside when he is done with his abolutions - I can't risk leaving him forgotten on the porch in these temperatures.
(added 1/7/10) Thanks for all the comments - you all are great! Maybe my problems really stem from the central air handling unit that resides over my office: http://www.scientificamerican.com/article.cfm?id=ask-the-brains-background-noise .