All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
There is no doubt that arrogance is one of the spiritual diseases from which the Muslims are enjoined to purify their hearts given the fact that the arrogant person is disliked by Allaah and is subject to His stern warnings in this regard. The Prophet, sallallaahu ʻalayhi wa sallam, said, “He who has in his heart the weight of a mustard seed of pride shall not enter Paradise.” [Muslim]
He, sallallaahu ʻalayhi wa sallam, defined arrogance as follows, “Arrogance means rejecting the Truth and looking down on people.” [Muslim]
Al-Nawawi commented on the hadeeth, saying, “The meaning of the phrase, 'rejecting the Truth,' means to be averse to it and deny it out of conceit and haughtiness, and the meaning of the phrase, 'looking down on people,' is to disdain them, seeing oneself superior to them.”
Verily, arrogance is one of the grave sins committed by the heart. Al-Hajjaawi said in his poem on grave sins (what means), “(Among the grave sins are) feeling secure from the plan of Allaah, severing the ties of kinship, arrogance, self-conceit...”
Repentance of arrogance is the same as that of all sins; the sinner must regret committing his sin, give the sin up with no delay, and resolve never to commit it again in the future. Please, refer to fatwa 86527.
In any case, the manifestation of arrogance to which you referred in the question does not have any effect on the permissibility or legitimacy of your knowledge, work, or income, nor does it constitute an act of disbelief in the slightest.
It seems that your question stems from obsessive whisperings and exaggeration. It is advisable that you repel such whisperings and abstain from thinking about them any longer.
Allaah knows best.