what's wrong with me?

As of lately I've been feeling sad with no reason, out of no where my heart feels heavy and I wanna cry but I don't know why. It's been happening repeatedly as of latley and it feels like I'm not genuinely happy cause of this and I don't know what's wrong with me at all. I take sleeping pills nearly everyday cause I can't sleep and they're over the counter pills no prescribed and my boyfriend said maybe the pills are making me have depression. 
Also this week I also forgot the passcode to my phone I didn't change it at all it was the same one I put everyday but I just forgot it which was strange to me how I could forget something I use everyday and my phone got disabled and was asking for the passcode so I had to reset my phone because I could not remember what it was and even now I still can't. 
I don't feel normal anymore.