to help you ID core beliefs.
Then google "How to change beliefs."
If you were actually arrogant, I don't think you'd be posting.
I think maybe it's this...
1) "How can she even be interested in anyone else when she has ME?!"
(She does think of other people and she seems interested. So it's not really that.)
It's more like...
2) I don't want her to think about other people. I want her to stop. I want her to only think about me.
Because then I could....
Because then I could not have to...
(what would you put there?)
Could make a list starting there. And keep tacking on the blue "Because...." stuff at the end of each sentence. Keep answering it until you can no longer "because" it out in both directions any further.
Then maybe you've discovered a core belief way down and the bottom there.
Could try it out. See what happens.
If you are in the habit of thinking things to yourself like "I must be arrogant, I stink, I am less than" you could work on changing your thought pattern habits so you aren't walking around being your own bully. You are not your thoughts. You are the person doing the thinking behavior.
If that kind of thinking behavior ensues in feeling like crap? Stop doing that behavior then. Do a different thinking behavior and make new thinking habits.
You could also spend some time doing self-respecting and self-expanding things (apart from not being your own bully) -- volunteer in your community, take up a hobby, learn something new, meet new friends and do friend things.
In short, do self-respecting behaviors and esteemable things so when the inner voice tells you that you are crap you can ANSWER BACK.
"I am a person who contributes -- I hold down a job, I pay my bills, I participate in my softball team, I am learning to tap dance, I foster kittens, knit socks for old people, and can build tree houses for children. YOU just sit in my head talking crap and contribute nothing positive anywhere. SHOO.)
I don't know what actual interests float your boat -- but you could figure it out and then start particpating in those things.
When you become a person of substance, you don't have to be "arrogant" and overinflating and talking up your accomplishments, contributions and skills. When you become a person of substance you don't have to be talking down to yourself either.
Your stuff can stand on its own merit. You know exactly your own worth and value. You can relax about it.