Firstly things get worse before they get better, but do believe me when I say they get better.
Secondly, please, for the love of god put down those scissors. You may think you're going to look like a supermodel with a pixie cut, but trust me you do not - and you will cry, for weeks. And please please put down the bleach. Dye your hair back to your natural colour and cut it out.
Thirdly, do not get your love-heart, italian writing, moon and peace sign tattoo's, you will regret them. The rose and the bird are fine - we like those.
Fourth, dump the boyfriend who treats you like shit. Seriously - he's not worth it. You meet an amazing guy at uni - and you move in with him. No I'm not kidding - you are not Bridget Jones after all.
And finally - we make it through uni! I know that seems crazy right now, but stick in at college, I know it's hard for you right now - but you're doing fine.
Love, your not that much older, but significantly wiser older self xxx
P.S QUIT SMOKING. NOW.