Feeling depressed, but I’m not sure where to start

I’d randomly start feeling sad and depressed out of nowhere, even in public, for the past few months. Weekends, where I’d usually go out and enjoy outdoors, were spent at home doing nothing and stuck in bed taking naps. I noticed this behavior, yet nothing was done to fix this.

Today I almost burst into tears on my way home in MRT, luckily I was able to keep my composure. Reached home, cried, and then here I am typing this post.

Should I get assessed if I have depression? Or maybe, what should I do?