Yes that does sound like depression. It can be really unnerving to know where the feelings are coming from if you don't understand them but depression is of course very treatable. But only a psychiatrist can make a diagnosis so the best thing is to make an appointment and explain it to them.
I am just don't feel myself anymore. I have more down days than good days. There are some days that I just wonder why I was even born. I feel like the whole world is against me, if that makes any sense. I have talked to family, but it doesn't seem to help. I haven't had any big losses in my life recently. I just don't understand what is wrong with me. I can't sleep through the night. I am lucky to get 3-4 hours of sleep at night. I feel like I am on overload.
Honestly only a psychiatrist can tell. But perhaps detail why you are concerned in the first place. You could speak to a talk therapist and see if a further referral is neccessary or if things are going wrong in a way that really concerns you make a direct appointment with a psychiatrist. It depends. The essential difference is that everyone does get depressed from time to time especially after life events that impact on them but clinical depression is something specific and makes you experience feelings of depression when things aren't really going wrong otherwise. That's as simple as I can put it but the website "Depression Central" can be of more information. But if you feel concerned it is worth speaking to someone about it regardless.