What you think about affects the way you act.
If you think you are not loved, weak, useless, falling short, then you are saying God you are not enough and you are crucifying Jesus again.
The negatives thoughts that come into our minds are ungodly beliefs and they cause you to act out what you feel. With every ungodly belief there is a lie attached. The devil is the father of lies, “When he speaks a lie, he speaks from his own resources, for he is a liar and the father of it.” John 8:44
God so loved the world that He gave His only son, and His love knows no bounds (Hosea 14:4). You are loved and not rejected. Jesus took all rejection on the cross so we could be accepted. “having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will, to the praise of the glory of His grace, by which He made us accepted in the Beloved.” Ephesians 1:5-6
We are strong only in Christ. Yes, we will feel weak when we are not drawing on Christ’s strength, “Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye double minded.” James 4:8
We are a chosen people and God has a plan for you, “For I know the thoughts that I think toward you, says the Lord, thoughts of peace and not of evil, to give you a future and a hope.” Jeremiah 29:11
“Finally, brothers and sisters, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable–if anything is excellent or praiseworthy–think about such things.” Phil 4:8