You and the walls you build up in your mind are the only thing holding you back from living to your fullest potential. We all build up these expectations and parameters of how we think the world want to see us instead of completely being you, and we should all stop. If you want to live the fullest most lived life just stop building up these walls, they are not helping you or anyone else for that matter. I myself have to consciously remind myself to stop these trains of thought in the moment as well.
When you are nervous about something and your brain is going through a list of unlikely things that could go wrong if you went out and did said thing, Ignore your thoughts. None of those things are going to happen so go out and do it. Especially if it could bring you joy or excitement because the world could use some more generally happy people focusing on things that bring them joy instead of misery.
Knowing that tomorrow is not promised has often lead to me to ask myself one question each time I feel as if I am in a rut, “Am I living a life that will leave me with memories or regrets that I didn’t do enough?” I happen to want to have a life full of memories to reflect on so this question gets me to redirect my efforts fairly quickly if need be.