So then the question becomes "What drains your energy?"
Is it the work environment? People you work with? Unhealthy boundaries? Too much work and not enough play?
You may also want to explore if you have low thyroid function for example, if you have not done so already.
Oversleeping/sleeping too much is often associated with low thyroid function. But please be also aware that this often includes the adrenals as well, as they try to pick up the slack for a weak thyroid, so they may also need support at the same time!