I Have a Question

You need a success !
Something you attempt and win at !
Once you have that you'll start to see life differently.
When you need certain things, job; income; being able to pay your own way etc. it's no wonder your self-esteem takes a knock !
And the longer that goes on, the more insecurity builds.
You question everything; you doubt everything; and on occasion it makes you feel as though you just want to hide away.
Been there ! Know how you feel !
Small steps. Little things you can do that will boost your confidence and belief in yourself !
So. Where can you get confidence in yourself ?
Well the easy answer is to hit the Internet.
YouTube has a series called TEDtalks.
Within it are folk who have overcome amazingly debilitating problems that they share with an audience.
There are topics on confidence; how to build belief in yourself. All kinds of things.
That's just to help give you a different perspective !
So then you need to look at what you can do for you !
If I want to build confidence in myself. I get my haircut ! A style that I know suits me and I feel confident wearing !
I polish my shoes ! Sounds daft I know. But folk notice that kind of thing !
There's no end of advice on c:v's out there.
From personal experience. All I'd say on that one is tailor each one to the job description you're applying for.
Most job descriptions(if they're any good !) have maybe 10. points that they want from their candidates. So alter your cv to encompass them.
Even if the job doesn't interest you. You might get invited to an interview !
Even better if you don't want the job as there's no pressure ! Gives you a chance to feel good about being you in front of an employer !
Make use of stuff you know.
Doubtless you know people. Friends; relatives etc. punt your cv round a few of them and ask them to drop them in their H:R depts.
Most jobs come from leads or folk you know !
There's even an idea that 70% of ALL jobs are never advertised !!!
Because it's too expensive; time consuming and a position they'd rather fill from within !!!
So do a bit of research and send the odd spec. letter ! You never know !!

i was very much like that until my 20s. i got interested in music and a few other things and finally got tired of feeling that way and being treated as inferior.

Its very possible to get over, it sometime takes time and the right people and support.