Hawk52: Am I alone with this or are there anyone else mentally damaged struggling too?
This is essentially the psychological phenomenon these sales are hoping to play on. No, you are not alone. The digital nature of the sales makes you rarely see the "clutter" which is good and bad. It's good in that the games don't "own" you as other items tend to, you don't have to carry them as you move or sacrifice living space as you collect them.
Still, you're dumping resources into them.
Now, you can look it it like "what else might I dump resources into" and realize that these games are probably a cheap habit. Or you can decide that they don't fulfill you in any real way and change your behavior (hard work).
Either way, I suggest you work on finding other ways to generate that positive rush buying something gives you, if only because it's ephemeral and hard to maintain.
I don't know what makes you "tick" so I don't have anything more specific to suggest.