"I DESERVE to be happy!"
That is one of Satan's most successful lies. We are a society of people who like to think that we are 'entitled' to everything we want. This attitude goes against the very core of Christianity.
It's not that God is opposed to happiness. He WANTS us to be happy. But He wants us to seek after TRUE happiness. Satan has us chasing illusions of happiness.
How do we know the difference?
If achieving this 'happiness' involves sinning against the very God who created us and who so lovingly sent his only Son to die for us, then we are not 'entitled' to seek after it. We will not find it there anyway because true happiness can not be found apart from God. It just can't.
If achieving this 'happiness' means hurting other people - then we do not 'deserve' this happiness. What gives us the right to seek happiness at another person's expense?
If achieving this 'happiness' means we have to break a personal vow or commitment to God or another, we do not 'deserve' it.
No matter the package Satan wraps it in - if the illusion goes against God's plan for us, it's just that - an illusion. It will bring us and the people around us misery and pain.