You can do anything to make your life better and make yourself happier. If you don't like what you're doing, then stop doing it. If you don't like who you hang around then find some new friends. If you don't like the way you look then hit the gym and start eating better. Life is what you make of it and if you don't make it great then, it's always going to suck.
Strive to do your best, put in the effort no matter how hard it is, andy don't look back at what was stopping you before. If you put forth an effort then you are looking for a way to achieve. The only way to achieve is by putting in the effort. You can make what you want out of your life, but that choice is essentially up to you. Nobody else can be the decision maker for you or even help you come close to what you want. You have to do things for yourself and not because other want you to, but because you want to.
There's always going to be something to go after in this world whether it's a promotion, a vacation, or anything else you want to do. You will always have to push yourself towards greatness because greatness won't just come to you. Don't settle for the crappy things in life, go embrace all of the great things that you can. Go to the park and look around at the trees, take your dog for a walk and let her run.
Enjoy your life and don't let anyone stop you or tell you otherwise. After achieving happiness in your life, anything is possible.