Aye many. Ive spent far to much of my life worrying what others think of me, worrying about things ive done in the past, worrying about the future and like Marky in the past few years have become an idiot when drunk. This combination has led me to some dark places BUT i think i've now started to make strides in the right direction as a person.
Started looking after myself more, cut down food intake, cut down alcohol binging, excercise more and constantly remind myself to live in the here and now. If i start thinking about the past or future i bring myself back to the present look at the world around me, tell myself that i have it pretty good and the world is a good place and carry on living in the moment.
Change is always possible. We are just the result of the decisions we have made in the past along with the conditioning we have gone through whilst growing up. If there is something that you feel is a negative trait in yourself it is entirley possible to change it with patience and perserverance. If you want to you will always be able to win the fight.