What is the supplication to be recited to get rid of negative thoughts that God will give something bad?

You must think well of Allah and expect good from Him; for He is the One who brings forth good deeds and repels evil deeds, and He is as His servant expects Him to be. So, rely on Him and do not care about the evil thoughts that Satan casts into your mind. Rather, seek refuge in Allah and ask Him to grant you good thoughts about Him.