Please go see a doctor, now, as soon as you can make an appointment:
"Depression" does not necessarily mean "sad," "crying all the time," "suicidal," or any of the other stereotypes. For me, it means "nothing seems to be worth the effort it takes to do it." It means "gah, my kids are annoying" instead of the bedtime hug being the bright spot of my day. It means that the only emotion I feel is annoyance, which once in a while pushes its way to anger (if I actually can make myself care enough to get that worked up). It means, damn, I'm tired and unfocused, and don't really care enough to try to get focused; so instead I'll just be annoyed with myself for failing to get my ass off the couch and focus and do the shit I need to do.
And most insidiously: it means that I go through my day feeling 100% completely like myself. Until one day, I realize that I haven't felt happy, or relaxed, or intrigued, or joyful, or thankful, or any of the other "good" emotions in literally months. It is like I am exactly the same me, but you carved off the top half (the happy, productive, engaged, grateful part) and left only the bottom half (the lazy, annoyed, unmotivated, selfish part). And you know what's even better than that? Because you feel exactly like you day-in, day-out, your depressed brain convinces you that you are normal, and the problem is the job, or the relationship, or that jackass that just cut you off, or some other -- any other -- external thing that is not you. And thus the disease perpetuates itself, like a virus, because it is so effective at preventing you from recognizing it as a disease. And then even when you do, it makes the steps necessary to fix it seem overwhelming and impossible, so why even try?*
If any of this sounds remotely familiar, you owe it to yourself to at least talk to a doctor. In many cases -- mine included -- depression is a real, physical thing, with an actual biological cause: my body does not manage its happy hormones correctly. As a result, there are actual medications that can turn that switch back on. You don't have to lie on a couch and talk about your mother -- I mean, sure, you can if you want to, and some people do have real, legit issues that a therapist can help with. But sometimes your body is just fucked up, and getting your neurotransmitters back in balance rights the ship.
*Me @2 months ago: Yeah, I pretty much have to be depressed. But, gah, how do I find a therapist? I have to look up my medical insurance, figure out what is covered, find a person. Yeah, they've got a website, but I can't remember my login/password, so I have to find that. Sigh. Then how do I know it's someone good? And they'll probably just tell me that it's my own damn fault, I'm just lazy and selfish and need to get my stupid ass off the couch. And I have to figure time off work, and kid coverage, and how do I know a client won't have a crisis? Sit and spin, sit and spin.
How it actually worked: DH forces me to the computer and sits with me as I look for a therapist. I remember my password second try. I determine that I am covered within 1 minute. I run a search for psychiatrists and find a couple who are within a few miles of me. Grand total: 5 minutes. Oh. Make a few calls, finally get an appointment a few weeks out. Go to therapist: surprise, I'm depressed! And some of my meds are making it worse! Change meds, get new prescription, within a week feel better -- not cured, but halfway to myself again. Think "I can't believe I thought this was going to be so fucking hard -- I shoulda done this months ago!"