Seriously, honestly, how to be happy when nothing good is happening?

How can one be happy when there is no reason to be happy, when nothing is going well?
There are so many people who are so lucky than we are.They are blessed with everything one can dream of or at least most of them.Well, yes theere are also so many that are even worse than us, but that cannot make me happy? For example, you may ask me to look at a handicapped person and then at myself, that maybe a reason for once in a while but I can’t always keep thinking about handicapped people as it won’t seem happier anymore.
Then how can one be happy when nothing is turning out good? When I am at my worse in academics and everyone else is improving and excelling.
When I feel nobody cares about me or really nobody cares about me?
When my health is also not good, or infact deteriorating.
When I cannot find out what am I good at or what I wanted to do with my life.
And when I am reserved, reticent and an introvert.
How can I be still happy? There might be some way.