The only constancy is change in this world until you've ossified internally into being just another stubborn dying boomer with one foot in the grave because you can't change any longer.
I've read that having a "schizophrenic" which I really took issue with their inept use of the word, identity, was the result of hyper modernity and hyper Capitalism leading to fragmentation due in large part to the demands of a society completely askew from anything remotely normal. But at the same time, if you had simply lived in a tribe or village would it have ever even occurred to you to formulate the concept of an identity itself?
Here's the thing if you try to use any kind of identity politics or putting on a uniform it's only disguing who you are, which can be fine unless you've tricked yourself into believing the masquerade. All clothing is just different costumes for the many roles we play, but putting one as is just as degrading and dehumanizing as wearing no clothes at all and being tattooed with a number in some 1970s uni experiment.
True identity is not static; it is an ongoing process. To the man who's done much in life this is not a question, because he has achieved and experienced much, and lost much, and thus he has become those things. The problem is in achieving nothing, you remain nothing. Most words are descriptors of roles. "Boyfriend." "Son." "Carpenter." Words for your roles in relation to others. Words in relations to your action and interfacing with this world. Being a seaman, or someone going out bird watching, they are the things you do that come to define yourself, which I forget who said it but likewise in a computer simulation it is a series of interesting decisions. To say that you are American is to say a lie because there's really no such thing except a hazy amalgamation of traits and stereotypes. What does it mean to be Finnish? It is the collective stories you tell and wisdom and history you share, but more to the point it is your specific way of relating to the world or, rather more importantly, in that case the one instance in which it's more about how the world is relating to you
and so broad as to be meaningless.
It is what you do and who you are and how you interact with the Other that is relevant for the construction of an identity and this is principally the reason why children and adolescents have issues with it, because theyve not yet had the time to make that series of interesting decisions by which to define themselves. And likewise while one action may not totally define you, at the same time if you stab your bandmate to death you are always going to be a murderer as that part of your identity, in which case learning to live with that fact and either embrace it or overcome it is perhaps the more interesting part of the process of a person's construction for their identity--namely, how they relate to themselves.
It is that last part for which a good number of people struggle, most specifically schizos, because of them suffering either a chronic and severe disconnect from others or most importantly an internal disconnect from themselves. On the off chance you have never experienced something like this a weed high can be the most wonderfully instructive psychotomimetic agent and pot remains to this day one of the most wildly unpleasant experiences I've ever experienced in this life, of which there are many. Note that you shouldn't try this regardless because apparently that segment of the population already a bit on the edge can be tipped deep into mental illness from it. You'll know immediately if you're one of those people.
Honestly it's not a terribly relevant thing to begin with and dwelling on identity is the absolute height of faggotry imho. I've always looked down upon ideological variants of it for this reason from far right to far left and everything in between. The only thing of relevance is what you do
in this life, and for those who do little or nothing the question of identity is of course paramount which they deflect into the abyss of identitarianism in an ill advised attempt to ignore and suppress the brooding existential crisis and swelling of anxiousness towards their conspicuous lack of fulfillment both inwardly and outwardly, with identitarianism and groupthink being the easiest and laziest salve because it tells you you have to do absolutely nothing when the opposite is the case.
The actual honest truth however is that no one is ever going to make the right decision every time. It's about the series of interesting decisions and how you deal with setbacks. It is often better to do something, anything, than to do nothing at all, which judging from your post is probably the crisis you're hitting which unluckily for you and hundreds of millions of other people is an inward revelation they're being simultaneously forced to achieve by having both distractions and constant noise and wasted motion like rats in hamster wheels.
So let me submit this to you, what do you even actually have to lose by doing something different with yourself? And is the cost of that transition greater than the monumental sacrifice you're already paying by not changing anything right now?