First, you need to visit your primary care doctor. Depression has dozens of root causes including but not limited to: underactive thyroid, mild allergies, vitamin deficiency, vitamin overdose, infection (often including tooth or gum infection), extended noise exposure, high blood pressure, low blood sodium (uncommon but easily overlooked), carbon monoxide poisoning, lead exposure, body injury (other than head, including over-strenuous exercise habits), anemia, wildfire smoke exposure, drug use/exposure (including secondhand tobacco smoke, coffee, and alcohol use as low as one can of beer per week), etc...
And we haven't even started mentioning neural and psychologic origins which are more common. But visit your primary care doctor first; the more physical causes for depression are often easier to identify (and thus rule out), easier (and cheaper) to treat, or more dangerous when left untreated. Ruling some of these causes out before you go to a psychiatrist can save a lot of time if your symptoms end up being non-psychologic in origin. To be clear, antidepressents CAN actually improve depressive symptoms even when the cause is something physical/environmental, which might mask the problem if the source is something like an underactive thyroid or lead exposure.