the big, bad habit

If you knew the assignment for this week, you'd probably think that my bad habit is procrastination. I was supposed to be journaling about this several days ago, but just couldn't commit to writing about one thing for three weeks; I get bored too fast with the same thing unless it is truly relevant to my life. Plus, I think that many of my bad habits come to the same root. Thus, I will focus on the bad habit of being unthankful.
I know it sounds silly, and you'd think it even sillier if you could see the incredibly lengthy list of my bad habits . But I want to be full of thankfulness because I know that this is the beginning of joy. A lot of my bad habits stem from the lack of happiness, and (and I emphasize this "and") the lack of joy. I can have joy and be unhappy at the same time, and given the fact that it is too easy to be unhappy in life, I am willing to learn how to be thankful.
When people tell me I'm a cheerful person, I think they are really fooled. I often feel too tired and worn thin to smile at another person. I can be rather gloomy at times, thinking about my current place in life. I want a nicer car, I want to be independent, I want to be thinner and beautiful like my older sister, I want to be smarter, I want to be funnier, I want to have a better job, I don't want to spend so much time in the car, I don't want to spend so much time on homework when I know that other people excel with less effort... These are a few of the things I think about all day long. In reality, I don't need much in life, and even if it is okay to pursue something like obtaining a better job, I want to be thankful meanwhile for what I have.
I'm not sure how to start. Changing my thinking is going to be a challenge much bigger than my biggest muscle... okay, a lot bigger than my biggest muscle. Breathing will be good. I'll start here.