Hello Wildcat, and a warm welcome to the forums.
We can't diagnose you as we're not qualified but I understand what you have told us but if it's possible can you go and see your doctor and I believe if you're 16 years of age you are entitled to see them.
I'm really so sorry for you.
Is it possible you put your comment in point form, and I only say this as you have mentioned so much the doctor will know how you are feeling.
Can I also suggest you do the K-10 test and you can find this if you click on 'The Facts' at the top of this page, it's a depression test, and again I can't say whether or not you have this.
Take this to your doctor.
Please let us know how you go.