There is your problem right there, you have to actually BELIEVE and truly want to get better.
And ps, your family doesn't dictate who your going to become. Addiction runs in my family. My mother is an alcoholic, my father is a deadbeat who had a "drug/drinking habit", my grandparents have both more then indulged in their fair share of alcohol, my grandfather was pretty heavy into coke in the 70s and now I start seeing signs of my aunt going from "wine-o" to maybe having a little bit of a problem. I see what happens around me and how it tears people apart. That will NEVER be me and i've learned to make lemons into lemonade. While most kids grow up following their examples I was learning what NOT to do. Take your experience and use it to your advantage.
Honestly, I was a pretty normal if a bit Emo kid until the depression kicked in, oh around 17. I had a ton of friends, a TON of friends, and pretty much any boyfriend I wanted. I had good grades. I went from that to extreme anxiety attacks, not graduating on time, dropping out of school etc. The difference between me and my family is that once I became an adult, I KNEW IT WASN'T normal, so I went to doctors to manage it. I still take the meds when I become unmanageable.
But to say that pretty much we can get better if we "REALLY WANT TO". Omg, really? You really think that I wouldn't love to be a popular social butterfly instead of someone who can't deal with the "social norms" without falling into a serious coma like nap afterwards? You know, it take serious work and I find little to no comfort in social gatherings, even "family" outside of the immediate. You really think all it takes is "hey, I don't want to do this anymore?!" Because I'm here to tell you right now that my life would be a thousand times easier if I could wake up one morning, snap my fingers and be a "normal girl" and accepted or at least able to overlook people looking down on my for my eccentricities.
It comes down to many many factors, some of which are genetic. SOME OF US CAN NEVER GO OFF THE MEDS. I am probably one of those people, and I resent it, and I fall off of them, the catch being I'm smart enough to know when I roll too deep into myself
Some people get better from therapy. Some people get better through meds. SOME people can get better through their spiritual beliefs. Some people find comfort in solitude or their animals. It all depends on the person.
It is most definitely not a matter of strictly "wish power" however. I, like you, saw what I didn't want to be....I don't want to be an obese, social outcast by choice, spying on the neighbors through the curtains while eating bologna because I'm too screwed up to get a job and can't won't get aid, nor do I want to be a crazy animal hoarder that goes outside smelling like cologne and cat pee.
I think that even though I suffer with depression and struggle to deal with other people, I am succeeding.
Anyway end rant, and don't take it personally, it's just that not everyone can say "I'M GOING TO BE NORMAL!" and make it so.