What is wrong with me

I don’t wanna say I’m depressed because I haven’t been diagnosed but I’m never happy if I’m alone, sometimes I’m happy around other people and I’m fine, but when I’m alone or it’s night and nobody is awake and there’s nothing to distract my self with everything goes down hill and I want to sh. So what I’m saying is why am I happy around other people and doing things but when I’m alone and can’t do anything everything gets worse, I wanna know what’s wrong like am I depressed my friends tell me I might be bipolar idk