It is often wondered how it was possible that Saba who was Oved Hashem for years upon years, following the advice of Rebbe Nachman could have possibly fallen into such a Yeridah simply by eating on the 17th of Tamuz. Saba was an expert in the Avodah of being happy, how was it possible that he fell to such depression.
It is know from Rabbanues books that each time a person ascends to a new level he must first break through the Husks / Klipos that surround this level. It can be assumed that the higher the level the harder it is to break through the Husks.
Saba reached the level where he was worth of receiving the Petek. Receiving the Petek is one of largest Aliyos that can be imagined. It can therefore be assumed that the Husks surrounding this level were very intense. No one can have any real perception into how it manifested or what Saba was going through at that stage but we know that it must have been very hard. Hard enough to cause the depression that lasted 5 days.