So I'm really confused as to whether I have clinical depression or not.

My depressive episodes are really weird. They sometimes last around 2 weeks (my best guess is around 13-18 days but my most recent episode lasted a month) and during this time it's absolutely horrible. I'm super suicidal during those weeks and I won't be able to stop crying (I would cry anywhere and everywhere). I also won't be able to stop SI'ing and I get super scared of myself because I think that I might actually take my life. It got super bad at one point where I started hearing and seeing things (happened to me last year; not that recent though) and it was almost like another part of me was haunting me and telling me to kill myself.

While I'm not depressed I feel ok-ish sad but I'm no longer crying and it's not interfering with my daily life anymore. But with this 'sadness' I get this weird anxiety where I get a weird feeling in my chest/stomach. But then sometimes at moments my mood randomly drops to depression and that lasts about maybe 2-3 hours or so (maybe a bit more).

Also another thing I should mention is that at the times I am happy I know I'm going to crash big time. The most recent time I remember being happy was late December 2014- January 2015 and then I crashed. But I don't think it's bipolar because I wasn't manic or such. I was just a normal happy person.

Have any of you guys experienced this before? You know what this is? (no, I'm not looking for you guys to diagnose me here; I'm just looking for suggestions of what you guys think this may be).

I'm not exactly sure what this could be. I don't want to go to the psychiatrist though because what if I'm actually normal then I'll just be wasting their time and my money.

Thanks