SABR (and anyone else who isn't feelin right): consider seeing a therapist.
As a former therapist, I can say this: it works (*).
If people complain about their knee hurting for weeks and weeks, we wouldn't tell them to suck it up, drop down in stakes, or even avoid the casino, we'd say: *get an appointment with a doctor*... if your tooth hurts, *go see a dentist*. (by the way - yes, I do appreciate that a poker pro's job might be contributing to stress... but if a surgeon is both depressed and hyper stressed by his job, we wouldn't say, 'try being a nurse for awhile, maybe that will help'... we'd say 'go see a professional for depression'. Also, it is true that some people will have to change jobs/careers to be happy. But try treatment first. A depressed poker player will probably be a depressed banker/insurance salesman/social worker/etc).
Depression is a defined, diagnose-able condition. Treatment helps.
(*) It works (to some degree) nearly 100% of the time if two things are true: the 'client' comes in open-minded and with motivation to change (i.e. not just going through the motions cuz their spouse/others made them come to counseling), and the client and therapist have a decent connection.
Those 2 things, IMO, are vastly more important than the type of therapy employed (**), or the experience/skill level of the therapist. (but some (thankfully low percentage of) therapists are complete loons, unfortunately. If you get one of those, try again
)
(**) But some version of CBT (cognitive behavioral) or ACT (acceptance and commitment therapy) are endorsed by me.
Peace