being tired is one thing
but whose idea was it that you need a boost in libido? Unless your partners are communicating frustration is it really that big of a deal? So long as you haven't lost it completely and it isn't affecting the sex you do have, I wouldn't worry about cyclic variation.
However if someone is complaining other than your own mind, maybe they could help you get some chores done or do them for you so that you get enough rest or come home to the house the way you want it, after those distractions and energy zappers are not part of the equation and you still think there is a problem, then there might be a solution to fix it
make sure that there is an actual problem and it isn't the typical cause which is mis-communication (close second to a partner behaving like an asshole)
If there is a actual problem, you might need to figure out if it is necessary. If you too tired and don't have the energy, do you really need to work that much? Sometimes we do have to suffer through struggling times, but if you don't have to, make sure that the cause of the problem is worth it.
Remember to evaluate whether or not the benefits are worth it, sometimes creating problems such as having no energy -- because you are working too many hours -- sometimes it's not worth it.