Live happily is a choice. Dull face or cheerful face is a choice.
Both energy exist . Positive as well as negative. It depends upon you to whom you embrace yourself.
Think of a scenario . where two people are in front of you . one is depressed with dull face, no cheerfulness , no enthusiasm. Same time other guy , cheerful face , inspiring smile, with passion , with enthusiasm , blessed. Second one is inspiring as well as happy.
Both are different , both had choices , what they choose was dependent on themselves.
So, Being happy is a choice, No matter from which disease you are suffering , no matter how stressed you are, no matter how anxious you are.
You always have a choice to think positive, to be happy without any reason . be happy. be blessed.