You might have a feeling that theres an invisible barrier between your head and the world.

Or that when you get external impressions you have to think what to do/say now before acting.

This is what I call living in your head.

This behaviour is often not limited to interactions, moreover being a deeper rooted problem spanning over various aspects of life.

A few examples:

Does it feel like you cant fully enjoy moments that should be very pleasing?

Or is there fear of saying the wrong thing to somebody?

If you find yourself agreeing to these questions I want to take a quick dive into simple psychology. (Let me say outright there are other reasons that could cause this)

This psychological „barrier“ that you can feel in your head is a way of your head to response to constants psychological „attacks“ on your self esteem, which you cant just draw away from.

This is often carried out by overprotective, controlling parents. (But it could be anything f.e. a sucking job you cant quit for any reason)

Its constant belittling, criticism for vain and all controlling behavior. Also doing even a minor mistake is connected to some kind of negative emotion.

You couldn’t (or still cant) just draw away from that because they were your parents / you cant quit.

You cope by putting up a wall in your head, to deflect the constant attacks on your self esteem.

This „wall“ is emotional suppression. Your psyches way of dealing with constant suppressed anger. You just get numb to anything that could cause emotion. So you also get numb to the anger you should feel by being attacked in your self esteem.

This wall is up and limits your interactions with people in general. You are not interacting. You are just reacting. Every action you bring is in fear of doing/saying something wrong. This leads to bad relationships and thus even a worse self esteem, even more overthinking etc.

Its crucial if you find yourself in such a situation to do everything possible to try and draw away from it. I would suggest to spend more time alone to perceive the world more without worrying about other people and slowly build your relationships.

Try to actively think about this barrier and literally get out of your head and live more in the present, perceiving and processing your surroundings.

Edit taking on a good explanation in a comment:

„This normally happens to people who grew up in environments where they were always criticised, their ego was always wrecked by family and friends, essentially your mentally in defensive mode, coupled with the feeling that if you complain and let your emotions out, no one will give a fuck. So everything is held inside and you mentally block yourself from the world cause because you automatically assume everyone is out to get you.“

This sums it up pretty well