It's easy to get negative because you get beat down. You go through a few disappointments and it's easy to stay in that negative frame of mind. Choosing to be positive and having a grateful attitude is a whole cliche, but your attitude is going to determine how you're going to live your life.
Don't ever criticize yourself. Don't go around all day long thinking, 'I'm unattractive, I'm slow, I'm not as smart as my brother.' God wasn't having a bad day when he made you... If you don't love yourself in the right way, you can't love your neighbour. You can't be as good as you are supposed to be.
Christmas is the perfect time to celebrate the love of God and family and to create memories that will last forever. Jesus is God's perfect, indescribable gift. The amazing thing is that not only are we able to receive this gift, but we are able to share it with others on Christmas and every other day of the year.