Am I going crazy?

So for the last few months I have been having crazy mood swings. I feel like at this point they may be getting out of hand. Like I will be really depressed, like I will think about how I want to cut myself or kill myself. I have not acted on any of these things but I just will think about it. Then I will be really happy and laughing or dancing or something the next minute. Also I have been getting really irritable with people or things but I won’t let it out on them. I don’t want to self diagnose but does anyone have any ideas of what could be wrong. I don’t want to tell anybody because I don’t want to look like a attention seeker. Also I don’t want to be put in an mental hospital or people think I’m crazy.
Cause I am a normal person but I just have been having crazy mood swings.