How can one get rid of intrusive thoughts as the month of Ramadan approaches, and what is the ruling on gathering saliva and swallowing it while fasting?

These whispers (waswas) are from Satan, and their remedy lies in turning away from them, seeking Allah's help, and sincerely resorting to Him. Not performing ghusl merely based on a delusion that one's ablution has been invalidated is part of turning away from these whispers. Shaykh al-Islam Ibn Taymiyyah emphasized that Satan whispers to everyone who turns to Allah, and the remedy is in steadfastness, patience, and persistent remembrance (dhikr) and prayer. Ibn Hajar al-Haytami stated that the beneficial cure for waswas is to completely ignore them; if one does not pay attention to them, they will disappear after a short time, but if one listens to them, they will increase until they drive one to madness. Whoever is afflicted by them should seek refuge in Allah and desist. As for collecting saliva in the mouth and swallowing it, it does not invalidate the fast, even though some scholars disliked it. Imam al-Nawawi mentioned that collecting saliva and swallowing it does not invalidate the fast, and Shaykh Ibn 'Uthaymeen affirmed that a fasting person swallowing their saliva is permissible, even if they collect it and swallow it, for it does not break their fast, as they have neither eaten nor drunk.