You must resist waswash. One is prohibited to do du`aa’ against himself. The Prophet (peace be upon him) said, “The Messenger of Allah (peace be upon him) said, “Do not invoke curses on yourself or on your children or on your possessions lest you should happen to do it at a moment when the supplications are accepted, and your prayer might be granted.” (Muslim)

There are certain ways for overcoming waswasah. They are as follows:

1- Seeking refuge with Allah from the accursed Shaytan, turning sincerely to Him and sincerely asking Him drive it away from you. Allah says what means, “And if an evil suggestion comes to you from Satan, then seek refuge in Allah . Indeed, He is Hearing and Knowing.” (Al-A`raf  7:200)

When the Prophet (peace be upon him) entered the mosque, he used to say, “I seek refuge in Allah, the Magnificent, and in His noble face, and in his eternal domain, from the accursed Devil.” (Abu Dawud)

2- Try to regularly recite adhkar at morning and evening, and the adkhar for going to sleep and waking up, and the adhkar of prayer, and other specific adhkar, and performing ruqyah as prescribed in Islam.

3- Do not leave yourself a victim for those insinuations by warding them off, stopping to think about them and to always do the opposite.

These are among the greatest means by which the Muslim can protect himself against the tricks, whispers and insinuating thoughts of the Shaytan

Allah Almighty knows best.