Too much of Doubts is a sickness which many suffer with. They make Wudu and then doubt whether they made masah or not.
They read Salaah and then doubt whether they read 3 rakaats or 4 rakaats. and many other such situations arise due to excessive doubts.
This is called Wahm in Arabic.
A person who suffers with the above sickness should read Ya Mu’minu 136 times daily.
InshaAllah, this sickness will go away.