Allowing these negative thoughts into our life limits our capacity, ability, future and who we were created to be. As a child of God, let's not forget we have access to the mind of Christ! We have access to God-thoughts we were created to think! And it is freely available through the word of God!
The word of God says that we are more than conquerors (rom 8:37), we have God's peace at all times (2 tess 3:16), we are sustained by God (Ps 55:22), we are complete in Christ (col 2:9), we have been given a spirit of power, love, self-discipline (2 tim 1:7), we have been blessed with every spiritual blessing in the heavenly places (eph 1:3)!
Is your thinking limiting you from being who you were created to be? Perhaps it's time to reboot your thought inventory and fill it with God-thoughts!
Do not conform to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God’s will is—his good, pleasing and perfect will.
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.