If you were always looking for at least one big reason to be happy don't look for it anymore. Your ability to look for it is already a big reason, being alive is already a reason to be happy. Breathing, moving, talking, walking, running are big reasons to become joyful in life because not everyone an do these things.
Some weak individuals were always complaining about their lives and even thinking about ending their lives. These people were very stupid and unappreciative with a very big blessing that they have. Other people were even struggling to catch their breathe and lives were already in danger but still wanted to survive and experience life even more.
If you are alive you can still change, if your life sucks right now, you have a very big chance to turn things around so don't even take your life for granted. Being alive means you are about to experience a lot of things, unlike someone who is lying in a deathbed who is very sick. If you are healthy, if you can do things then be happy for it.
Life is not perfect, if you are expecting that life is all about fantasies and fairy tales then you should wake up. Life is all about experiencing different kinds of emotions. Fear, joy, happiness, excitement, anxiety, despair, anger and pain. You are very lucky if you can experience a lot because some people can't even walk or cry or jump. Some people were born paralyzed so be happy if you are so alive and can do a lot of things.
If you are alive, you can become rich, poor, popular, wealthy, passionate, talented, healthy, good looking, great or anything that you want. You can do anything with your life, your life is a big ticket to happiness or an exit for destruction. It is up to you how are you going to spend your life. It is up to you how to nurture it or destroy it so don't ever complain that you are not blessed or you are so unlucky. Life is how you live it.
If I were you, I will change my mindset now and look for some good things to do, look for some things that will make you even happier. Be passionate in what you are doing, be helpful, have something to do for the rest of your life that will make you proud. Look for some goals and achieve it. Develop some skills and be great at it. Play with your life, stop being sad and dramatic. Stop looking like an emo spoiled diva who all does is look for sympathy and a shoulder to cry on.
Be the best that you can be, become a greatest version of yourself. Let me remind you again that life is not all about being happy. If you will understand that life is a rollercoaster of emotions and you are ok with it then your life will become pretty amazing.