I do feel like that a lot. For me It engenders a fear of the future because I know the future is going come the adult challenges that I am not going to be able to handle or at least handle adequately. I certainly feel like a child in an adult world and that in many ways, similar to the ways you mentioned.

What helps me sometimes is that I have a crystal clear and sharp focal point. It is something I aim to do with crystal clarity. I got the idea by reading books by psychiatrist Viktor Frankl and by seeing the movie "Schindler's List." What I try to do each day is help people. This is my overriding and ultimate concern. If I can help even one person, then I feel my life is justified.

I read the biography of Oskar Schinder and he was pretty much a mess as a person. In a way he was like a child living in an adult world. His life was a mess. He had bad habits. His relationships were a mess. His career was pretty much a mess too, a series of business failures. But he is not remembered for any of that. He is remembered as the man who saved the lives of so many, many people during the Holocaust.

I am nowhere near his equal in that. I am not fit to untie his shoes. But I think and hope that I do help people and if the rest of my life ends up in the toilet but I am able to help people, then I was be content. Then at least in one area of life, I will not be just a child in an adult world.

I think, with the philosopher of Pascal that there are various orders. There is order of the physical realm, the order of the mental realm and the order of charity. Each one is higher than the others.
Carrying a heavy rock can be an achievement in the physical realm. Inventing a medicine to cure small pox is an achievement in the mental realm. What Schindler did was an achievement in the realm of charity which I believe, rightly or wrongly, is the highest realm and the highest kind of achievement.

After Schindler saved all those people, his life did not really improve much. He was broke all the time and had to go door to door selling light bulbs. He was all alone too. But I think he made his mark in time, history and eternity.

I also think it is important to cultivate the child inside of oneself because that is where a lot of energy and joy of living comes from. It is sad when people become too adult and are so lost in joyless striving that they lose the joy of living.

Of course I could be wrong about this and everything else I wrote. I am often wrong about stuff. But that is my opinion as of today.

There are of course times when I lose my focus and feel a dread of adult realities.