What if my negative thoughts just feel like who I am?
The problem with those thoughts is that they resonate with your personality and become enmeshed with it. It's easy to reject a lustful thought, because obviously it's sinful. It's much harder to reject the thoughts you don't see as sinful: pride, egotism, self-justification, righteous anger, despair, anxiety, fear. We integrate them into our personhood and think, that's just me, that's who I am.
But it's not who we are at all. It's a complete distortion, taking aspects we're inclined to and exaggerating them until we lack all emotional equilibrium. The key is twofold. Yes, pray, but also reveal your thoughts to your priest or spiritual father: I'm having these thoughts and I feel anxious, I think these thoughts are causing me damage. Feelings don't come from nowhere.
They are the byproduct of a definite thought process. If we eradicate the thought process, the anxiety goes away. If we're not trying to control life, anxiety gets solved very quickly. If we're not dwelling on perfectionism, despair doesn't happen. If we're not thinking we're better than other people, righteous indignation goes away and we become humble. The thoughts have to be corrected into a right way of seeing the world, and then we cling to our repentance, the Jesus Prayer, and humility, which God has given us to correct those tumors in the soul.
When a person corrects their thinking, their whole life changes and slows down. Their heart becomes settled, and they rely on our Lord Jesus Christ. As he says, my peace I give to you, not as this world gives. The peace of Christ is beyond all understanding, because no matter the circumstances, the person is at peace, not ingesting anything that makes the soul sick.
John 14:27

