I wouldn’t be so naive to suggest that every location in the U.S. has a free mental health clinic, but most of them have a local government-run clinic which has a sliding scale that runs quite close to “free”. A clinic local to me goes all the way down to $6 for an hour-long talk therapy session (and $3 for a session with a psychiatrist to work with medications), and inability to pay for your session won’t mean you don’t get the session, though running a big enough balance may affect your ability to get additional sessions.

If medication is needed such clinics typically work from samples donated from local doctors (who get them from pharmaceutical companies) and there are programs for free medications, maintained by the drug companies themselves.

There are free hotlines (usually to prevent you from committing suicide) but they aren’t good at treating chronic conditions, only for talking you off the metaphorical ledge. They don’t keep records so they aren’t all that good at helping you spot bad behaviors and bad habits which are reinforcing your depression.

Exercise (such as planting trees) is a good way to improve mood, but do it in conjunction with some form of talk therapy. You’re depressed because you have attitudes which are constantly reinforced by your bad habits, but your bad habits are largely unnoticed by you. Depressives and other folks with mental illnesses really do benefit from an outside observer to point out bad speech patterns and bad behaviors which can be corrected only if you are told they are there. Once the outside observer helps you understand what you are doing that reinforces the mental attitudes that keep you depressed, you can work to change yourself for the better.