Let Yourself Be Happy

Recognize that you make a deliberate decision each time about whether to let yourself feel happy so focus on the reasons to feel that way and decide to enjoy life more without doing more than choosing to do so. Rethink all aspects of your life and surroundings and choose to focus more on those parts that make you happy whether by making you proud or simply lucky since you are not worse off when you could be. You can find many things to be happy about even among stuff otherwise having the opposite effect on you.
There are degrees of happiness but all are good and worth choosing. And there is an important distinction between being unhappy and being not happy. Let go of what doesn’t help you feel happy and learn to be content with the less than perfect but still fully adequate.
You can and should reselect your role models and simplify your goals when your earlier ones don’t work out. Take new looks at your world - your family, friends, work, body, health, and home. Many aspects of those can make you happy if you focus on those parts. Even the mundane but relevant details of your life like your hair, food, and clothes can be sources of happiness if you’ll let them. You make the difference. You don’t need permission from anyone else to do it since you are happy when and only when you decide to feel that way.
Likely your increased happiness will be noted and by your example you can help others be happier more of the time too without preaching about it.