feeling empty

Right now I'm feeling lower than ever.
It's taking all my strength not to self harm or to purge. I don't know why I want to so badly, it's not like anything has happened to me recently that's made me feel this way. Yesterday, or the day before that -- I really can't keep track when I'm like this -- I just suddenly started feeling empty. Like my life is pointless, like I lack purpose. I feel alone and depressed and...disgusting. Nobody loves me. Nobody cares for me.
I feel very...anxious and antsy right now. For some reason, I started getting crazy thoughts in my head that I never really thought about before. To some, they seem normal: things like dying my hair brown, getting a choppy haircut, getting a tattoo and a belly piercing. These things I've always thought would be cool to do but I was convinced that I would never. But now, I want to more than ever. But the question is: why? Will doing these things suddenly make me feel that I've found a purpose? Will they fill the emptiness that has consumed me?
I don't know. All I do know is that I just want to go get drunk, be stupid, knock down mail boxes, and even... god forbid... DO DRUGS. not hardcore, just weed. I've never done it before. I'm feeling extremely rebellious right now, which is kind of scaring me, but it's also oddly revitalizing.
I'm thinking of setting new goals and incorporate these into the goals. I don't have a scale right now, so I'll have to wait a couple days and sneak out and get one. Who knows, maybe I've already hit goal 1?

105: haircut...side bangs, choppy layers?
100: dye hair brown...if I still want to by then that is :/ (I'd really like to, but as I have such a unique...and apparently envied...natural hair colour, I'm terrified it won't come back 100%)
95: tattoo on hip...either stars or a funky heart. not sure if I want back or front though
90: belly button piercing
85: try weed. just once.
80: umm...happiness? chyeah right. Maybe I'll just settle for quitting my shitty job and getting an eyebrow piercing. I've always wanted one but we aren't allowed to have them where I work.

oh yeah, and the other day I told someone I'm 5'3.5"...which is understating (I thought I was 5'3.75"), and was told upright that I can't be taller than 5'2", 5'2.5" max. ugh I wish I had a tape measure here so I can find out for myself.