Take internet diagnoses with a grain of salt but honestly this is a good list of things to at least investigate. Sleep health, diet, and exercise would put 90% of doctors out of business if people just took care of them (source on that: my doctor).
I would add depression to the list. Depression is not what most people think it is, and it can manifest with some of the symptoms listed here. Talk to a general doctor about it as a starting point.
Also it should go without saying that any addictions that may be involved should be addressed as well.