A foundational obstacle to self-esteem which undermines any amount of internal work or external achievement:

Asking for permission to exist, thinking that any interaction with another’s existence is an intrusion until proven otherwise.

There are a couple of ways this expresses itself:

Treating yourself as unwelcome by default in every space and looking around for cues nervously, expecting only transactionality and therefore never doing and receiving things whose main component is transient fun & joy.

Waiting for others to set topic and tone to discussions.

Treating spontaneous calibrations as mistakes and therefore failing to calibrate, and small mistakes as proof of massive personal ineptitude, pedestalizing others who are at the same level as you apart from a single factor like money, hyperspecific intellectual strengths and talents or specific success in a field.

Believing, somewhere deep inside even if not consciously, in validation of personhood by full consensus. Rather then an inviolable first principle of existence itself, so, failing to see rejection and dislike– including from yourself to others– as human/social rights that are helping you be safe, happy and find your tribe.

Framing good traits that have failure modes as defined entirely by their failure mode (sensitivity –> oversensitivity), therefore framing all of one’s best and most likeable traits as bad instead of simply learning to install guard rails (ex. humility, manners, clarity, slowness, playfulness)

Whichever way you plan on evolving from this, whether therapy or touching grass, introspection or external action, its firestarter realization cannot be skipped or detoured around.

It is a profoundly split-second decision that you must bring yourself to say and feel fully, and then let it soak in slowly over time.

Your existence is a matter of fact. So is everyone else’s.
It is not given, gifted, conferred, stolen, conquered, borrowed, earned or taken.

It is simply there.
It is ours.

Success or failure, in relationships or careers, cannot alter it, as they are simply offshoots or chapters of our existence.

The parts of our brain we want to remove from existence behave the same way to that aggression as we do when they do it to “us”– the we that we think of as the main character of our story– or when we do it to someone else.

But they all deserve to exist, even the dark ones, and we can enjoy and appreciate their existence, and this has nothing to do with whether they act on the material world as your conscious mind– that is, our main character– does.

The mind is a pattern-matching and pattern-creating machine, which creates spontaneous personalities in reaction to everything from miniscule to life-defining moments.

We don’t need to take these personalities seriously or lightly. We had no choice in their making.
They do not exist materially even if on interrogating them some have deep lore and full lives, they become significant– useful or harmful– only in the context of our conscious and unconscious employment or disparagement of them.

Conflicting thoughts in our own minds and people outside in the world rubbing up against each other can be pleasant or unpleasant, but this does not take away from and rather only reinforces the deep, sentient property of the universe that is your existence.

Never ask for permission to exist, especially from yourself.
Never force another person to feel they need to earn theirs.

I think this is closely related to what Sascha Chapin calls “deep okayness”, you might like to read that article here, especially since it gets into one very specific answer for “ok, so how do I do this?”