I think I might be depressed, should I go the drs?

I honestly i don't know what to do. I don't know if I'm being paranoid or overreacting and just need to get over myself, in which case I'd rather not bother a doctor about it, if you know what mean? I'm an 18year old girl, in sixth form studying alevels and applying for Uni.

There's a history of depression (and other mental illness such as alcoholism that sort of stuff) in my family and I'm really scared I might have it. I don't know what to do, we dont talk about things you see, I don't know what depression is supposed to feel like and I don't know what normal is supposed to feel like so I have no idea where I am

I haven't had the most ideal home life (but who does?) I don't like my appearance (but who does?) I'm really stressed out (but honestly, who isn't?) and I just feel as though I want everything to just stop because there's no point, and I can't do anything so why even bother trying, or getting out of bed or anything really and I don't know if that is normal ? I think I get overly stressed about stuff too, last year I got bald patches all over my head that my dr said was due to stress (which did wonders for not stressing me out obviously, no 17year girl wants a combover)

I think maybe it's a phase sometimes because I get bouts of being really happy, and just what I want to feel like all the time but it doesn't last and I don't know which is supposed to be the right way to feel? I'm scared of making an appointment for the doctors and then, nothing I feel alright and I've wasted every bodies time and someone who needed the appointment could have gotten it

I've seen people in my family and some friends suffer from depression and I feel as though if I say that I'm scared I may have it to any of them then itll seem as though I'm mocking them? Like what have I got to be sad about, sort of thing even typing this feel extremely silly but I don't know what else I'm supposed to do?

Are there like warning signs ? Are there any preventative measures I can take so I don't get it?