Yes this is normal, even the companions would suffer from it, when they were with the prophet (saw) their emaan would go really high but when they returned to their lifes it would go lower.
Every believer suffers from weak or low emaan once in a while; as the Prophet (sal Allahu alayhi wa sallam) said, “Emaan wears out in one’s heart, just as the dress wears out (becomes thin). Therefore, ask Allah to renew emaan in your hearts.” [Mustadrak Al Hakim, Authentic]
Low emaan can easily plunge one into sorrow and despair, as emaan is a safeguard from this. When one suffers from low emaan, it paralyzes one from doing good deeds and removes the productivity in one’s life and worship. One of the beautiful aspects in our deen is that Allah and His Messenger have prescribed actions for us when we are suffering from weak emaan and sorrow, and one of the most potent cures is duaa.
This week’s supplications include two duaas that everyone should memorize to help you during these times of low emaan, sadness, and times of distress.
First Supplication
The first duaa was narrated by the Prophet (sal Allahu alayhi wa sallam) in Saheeh Bukhari. It is narrated in many ahadeeth that the Prophet (sal Allahu alayhi wa sallam) would consistently make this duaa, and many of the Companions heard him repeat it over and over.
اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ الْهَمِّ وَالْحُزْنِ وَالْعَجْزِ وَالْكَسَلِ وَالْبُخْلِ وَالْجُبْنِ وَضَلَعِ الدَّيْنِ وَغَلَبَةِ الرِّجَالِ
Allahumma inni a’udhu bika minal-hammi wal-Ḥuzni wal-’ajazi wal-kasli wal-bukhli wal-jubni wa ḍala’id-dayni wa ghalabatir-rijal.
O Allah, I take refuge in You from anxiety and sorrow, weakness and laziness, miserliness and cowardice, the burden of debts and from being overpowered by men.
http://muslimmatters.org/2010/02/10/...and-anxiety-2/