Happiness is your decision. Yes, you decide if you will be grumpy or happy. To let your emotions be subject to the wind is to give up control over yourself. That is not only a bad idea, it’s dangerous. If you are not in control, the enemy will happily take over.
Why are you cast down, O my soul? And why are you disquieted within me? Hope in God; For I shall yet praise Him. (Ps. 42:11) Have a good talking to yourself. Snap out of it. Your happiness is a heartbeat away. Are you sick of being unhappy? Then decide right now, this second, to stop it.
Tell yourself, “I choose to be happy. I will trust God and bless Him for all that He has done for me.” It may take repeating a few times, but keep at it. You can be happy and you can be happy every day. Put your life in God’s hands so He can help you with the things that are going wrong. If you don’t trust Him, He can’t help.
Happiness isn’t something only rich people have, or lucky people have. Happiness is a decision. If you are unhappy, then it is a choice that you have made. Chose to unmake it.