Is performing ghusl for major ritual impurity considered both ghusl and wudu'? And what is the remedy for excessive waswas (whispers/doubts)?

The cure for obsessive whispers (waswas) is by trusting in Allah and turning away from the devil's whispers. A Muslim should fear Allah, rely upon Him, and ask Him for well-being in this world and the Hereafter, while knowing that all matters are by the decree of Allah.