Half the reason I got my FitBit earlier this year was to track my heart rate. The last 2-3 months have been particularly bad for me, and that's been reflected in my heart rate presumably due to the stress.
Six months ago I was working out less but my average resting HR was an excellent ~55. In November it was mostly at 69, despite me being extremely fit (semi-unemployment leaves lots of time for the gym).
The past couple days I've been watching it drop, and it's now down to 60, and that pretty much reflects how I feel too. Much less stressed, plus I'm eating better now that I actually have work to occupy my time.