except fasting; it is for Me

Assalamualaikum wbt,

As browsing youtube to RnP (research & preparing) for the upcoming Ramadhan Qareem, this hadith caught my attention *and it always be :
Al-Bukhaari (1761) and Muslim (1946) narrated that Abu Hurayrah (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Allaah said: ‘Every deed of the son of Adam is for him except fasting; it is for Me and I shall reward for it…’” 
Once I have an infographic showing how fasting can overcome our depression in more spiritual ways, I already do it *im not trying cause at that time am really cracking inside out. Sorry that I lost it somewhere and I cant put it in here. *sobs.
Basically the infographic written was how to relief your depression by doin fasting. The steps that I can recall are :

1. Sleep early and dont forget your prayers before sleep and nawaitu for fasting tomorrow.
2. Wake up early and have a simple sahoor, a glass of water or milk with dates (3 pieces).
3. Dont forget to tahajud, ask for Allah’s mercy and forgiveness.
4. Have a very productive day, do as much deeds as you can like perform prayers early in time, smile, give sadaqah etc.

5. Break your fast with syukoor & pray that your fast will be reward by Allah. 
So how really can fasting overcome our depression? 
We, human, spend every daily life asking ourselves what should we eat today? Where should we eat? For God sake, its the most hard question ever in the world. And what we eat can bring harm to ourselves such diarrhea, food poisoning, obese.. etc.
Otherwise, while we are fasting, we leave our dunya, we leave everything in dunya; the food, the maksiat, the all useless talking. And no one know we are truly fasting except we and Allah. We need to accept that everything happens in dunya make us depress. *since cannot decide where to eat also makes frustation slightly.

The fasting person may be in a place with no other people around, and he could eat or drink that which Allaah has forbidden to the fasting person, but he does not do that, because he knows that he has a Lord Who can see him even though he is alone and Who has forbidden that to him. So he forsakes it for the sake of Allaah and fearing His punishment, seeking His reward. Because of that, Allaah appreciates his sincerity and singled out fasting for Himself from among all other good deeds. Hence He said: “He gives up his desires and his food for My sake.”  

“He gives up his desires and his food for My sake.”  

Apa lagi matlamat yang paling murni selain meninggalkan segalanya hanya kerana Tuhan kita iaitu Allah? 

Some extra stuff that I found helpful. ^^
Extra : PDF Panduan Puasa Ramadhan oleh Ustaz Sarip Adul [baca/download]
Powerful explanation about the hadith by Shaykh Muhammad Salih al-Munajjid can be found [here]

Balighna ya Ramadhan. Allahumma amin.