If you think you might be depressed, it’s best to look for a psychiatrist who can make an assessment. I’m providing this info for educational purposes only, please don’t diagnose yourself.
To be officially diagnosed with depression, you’d need to have at least five of the following symptoms for at least 2 weeks, and at least one of the boldened symptoms needs to be present:
Depressed mood
Loss of interest/pleasure in almost all activities
Significant weight loss or gain without dieting or significant decreases or increases in appetite.
Sleeping too much or too little nearly every day.
Moving too much or too little nearly every day in a way that’s noticeable to other people.
Feeling fatigued and devoid of energy nearly every day.
Feeling worthless or inappropriately guilty nearly every day.
Having brain fog and indecisiveness.
And, finally, having thoughts of suicide.
More goes into the diagnosis (like for example ruling out medical conditions and substance use), so once again, please don't just diagnose yourself based on this list.