I don't comment on here much, but I just had to this time. I noticed something that I don't think anyone else did, how young you are. You were born a year after me so you're 17? That is WAAAAY too young for some of the problems you're having, but, my life is very similar to yours right now, so I'm going to be your personal depression coach, if that isn't creepy.
First, a little info on me:
I'm 18, and I would say that I've been clinically depressed for about 1.5-2 years, but I've been unhappy for maybe 3.
I do not take any pills, and I do not want to, personally, I feel like I would have problems with admitting that I need them and what that would do to my confidence in myself.
I have never dated anyone, never even kissed a girl, and I am extremely lonely. Rejections from 3 different big time crushes, and the emotional fallout and loneliness are the main causes of my depression.
My dad passed away a couple weeks ago, it hasn't hit me yet, I am generally desensitized from the depression, but also, seeing as I have not experienced many, major tragedies take a long time to hit me.
I do have a job, but it sucks, you're not missing out on much, I don't see why that is such a big deal to you.
My point is that you, me, us... we're teenagers, we are emotional wrecks. I have no friends who are depressed, but they are perfect Christians living perfect Christian lives in their perfect Christian homes, or they are constantly high. My mom was depressed as a teen, though, a lot of people were. So, you seem to have a big, legitimate problem here, the same as mine, and I want to help, as in getting you through this, because even if pills make you feel better, they're not going to fix anything.
First thing I can say now is your ex is the source, that is so obviously clear to me.
But, it's 5:30am where I am and I need to go to bed, but I want you to bring up your concerns to me one at a time, and we will deal with them, on here or in PM, anything from your ex, lack of a job, you mentioned weight loss, self-esteem, anything. And I will attack later using only what I have learned, and still am learning, through personal experience.