It's difficult to be fully happy when you're avoiding dealing with important issues and your brain is clogged with things you haven't resolved. It's impossible to grow and fully enjoy life if you don't move past the things that hold you back. Think of the issues in your life that require attention and healing and work on one of them until it goes away. You don't have to do everything at once, just take one small step at a time. When you're done with that issue move on to the next. The act of working on things over time will help you be happier.
Some people spend their whole lives avoiding the very thing they really need to examine. A huge part of being happy is deciding to take action to heal yourself and move beyond your hurts; to become healthier and more whole. It's not an easy process, you might even need professional help, but it leads to true joy and fulfillment.