How do I know if I'm some sort of depressed

I'm having one of those hard days at work that forces me to reevaluate my situation in life. I hate my job and I feel like it's been my life for the last 7 years. I'm very competent but that's all I believe I'm capable of achieving.

I'm not sure if things are getting harder or my cracks are beginning to show but it's probably both.

I know plenty of people have it worse than I do, but I'm still feeling hopeless. I hate to be dramatic but it's therapeutic writing this out and to tell someone