Unlike most answers, depression isn't that easy to deal with. Long story short, my 'friends' started treating me badly at 17, and I felt unwanted- like a burden most of the time. Within 2 months, I was isolated by my 'friends' school every single day, and was constantly placed in situations where people told me I was just 'nothing.' My other friends laughed at me and blocked me on social media, which convinced me something was wrong with me. I was so convinced there was something wrong, that I would not go outside of home, and would run to the bathrooms during classes, as I developed severe social anxiety.
In the next 2 months, the social isolation got worse, and for some reason, I began feeling numb and empty- like there was nothing I could feel. Not happiness, not sadness - just empty.
IThis feeling remained, as I constantly convinced myself to place myself in those situations because I wanted to know what was wrong with me.
I wasn't suicidal but was self harming for a year and a half throughout this time, and it took me that long before I found help.
If you think you are depressed, dont wait for 2yrs like me, get help immediately.