It is important we take care of our Imaan. The sahabah (ra) used to feel their Iman getting weak so they would do many things to renew it. One example was they used to read ten verses of the Quran, understand them, memorize them and apply them and then move onto the next verses
The Prophet (pbuh) also talked about extremists. These are people who are blinded by the light, not guided. When you do too much at once you become overwhelmed and end up with no Imaan. The dua to help us is “Oh turner of Hearts, make my heart firm upon your path”.