If you've ruled out medical cause and diet... and you're "just" exhausted from a long day... here's the best trick I know of:
Go ALMOST home. Stop somewhere (within 2-5 minutes of home, or you'll have to drive, which negates the whole thing). Coffee Shop, bookstore, restaurant, wherever. Stay there for 20-30 minutes and do nothing. Read, goof of on your laptop, call a girlfriend, read the paper, whatever you would do when you got home if you could. Use their restroom to change out of your work clothes and into something ELSE. (Why IS it that work clothes feel so different from street clothes?). Wash your face. Get your UMPH! and your grins back!!
Then go home, excited instead of exhausted, and give your hubby the same treatment. Literally say "Baby, go take half an hour to yourself, I got this". You'll be so much more energized for having taken a little time for yourself that you'll be able to walk in the door and hand-off immediately and even WANT to (instead of the "but-i-needa-come-home-from-work-and-relax-for-a-few-minutes!!! wail... c'mon we've all done it, mentally or out loud). Which HE will appreciate bigtime since he hasn't even had the peace and quite of being alone in a car for an hour.
As each of you consistently start getting that peace and quiet each and every single day... you'll wonder how on earth you ever got on without it.
((BTW... I know hundreds of couples now who do this, and sooooooo many of them tried to "do the same thing but at home"... and I only know one couple who it worked for. Here's why: The moment the working spouse comes home, the sahs hear's the "bell". It's like being forced to sit in class and wait after everyone else goes to lunch. It's 1000 times as hard/ boring/ exhausting to be "on" when you're watching someone else on break. So the sahs gets resentful, even if they get their break afterward. But when the WS takes their 30 minutes of me-time elsewhere (as long as it doesn't turn into some ridiculous 1-4 hours), the moment the WS gets home is a flood of relief.))