You can't be happy if you don't feel safe because you'll spend all your time trying to avoid perceived dangers rather than enjoying life. One of the most basic needs a child has is to feel safe. Many people didn't have this need met early on so they spend their lives trying to compensate for the lack of security they feel deep inside. This is a recipe for not being happy.
The key in life is to resolve the issues that get in the way of discovering who you really are and sharing it with the world. If you don't feel safe at the very deepest levels of your being then it might be worth your time to pay some attention to that feeling and heal it so you can increase your feelings of security and move forward confidently. You don't have to fix everything all at once, just work on one area where you don't feel safe, heal it, and then move to the next. It will take some time and effort, but eventually you'll be able to enjoy life courageously.