Hmmm... I kinda understand the way you feel... loving someone so crazily that you could do almost anything for her... but will this help? Making your loved ones happy by sending her things she likes, love letters, express your feelings and so on are part of the process. In either way through the process there'll be either success, or the terrible failure. Yes, indeed you couldn't bear your love towards her, and somehow without good control you fell off your path, causing problems you having now. But just let her go... I won't say just go and forget her, cause it's really difficult to forget someone whom you loved... but she's just out of your grap, so just let it go. There's some old sayings which mention:
If you love something, let it go.
If it ever comes back, it'll forever be yours.
If it never comes back, it'll never be yours.
Based on these words I've manage to survive till now... so I hope they will help you too. Again, 17 years old is still the begining of your wonderful journey of life. Don't waste it. Go ahead and try finding other girls... surely there'll be someone out there suitable to you, right? Again, I remember some sayings:
Don't let a tree detsroy the whole forrest...
I hope you get well soon, and move on...