I don’t know what to do anymore.

I think I’m depressed. I feel like it’s always been a problem since I was a kid. I was always moody and felt so sad all the time. I felt alone and it’s like this darkness is just around me all the time. I feel like I’m rarely happy. I just feel this pain in my chest all the time. When I’m happy, it’s the best thing in the world. But when I’m sad then I truly feel it. Nothing can get me out of it when it happens. I don’t know what to do anymore. I don’t know how to fix this. I just feel like I have to be perfect all the time and I beat myself up when it happens. I just want this sadness to end. I wanna be happy but I don’t know where to start.