It's every person's own responsibility to take action and do things that increases their positivity and happiness, to take an active role in making yourself happy. It's not something to simply be given, nor something that happens easily. It's a struggle, one that you keep facing everyday. But you do have a choice. Either choose to have a positive look on the day, to think about all the thing's that are good in your life and what you're planning on doing in the future. Or you can do the opposite. It's up to you. You, and you alone is the one that could make it happen.
As for your thoughts, why is it that you don't believe you deserve the same chance as anyone else to be happy? What's the reasons behind it? Finding out the cause, is a vital step to solving the issue. You can't decide the consequences, but you can chose what you do with what's left.
”In order to succeed, we must first believe that we can.”