I'm going to sound like I'm all up in your face criticizing, but there are a number of things in this post that are exemplary of beginners, and I think a lot of people could learn from a close examination. This is a fisk out of love.

Quote Originally Posted by rmariani
I don't know what I did wrong. I may have overplayed a couple of hands due to the lack of quality hands that lead to some loosiness
A lack of quality hands does not lead to looseness. Your decision to start playing loose leads to looseness. Don't make that decision.

Quote Originally Posted by rmariani
, but nothing that justifies such losses. I've also tracked "money lost by stupidity" in the last 4 days (31,7,10,34). It's strange that the day where I won more money I have the same "stupidity level" as the day I lost more .
I don't really like this. Yes, you make some bad plays and you should correct the mistakes in your play, but a "stupidity tracker" is just beating yourself up over it. Don't jot down the amount you lost; jot down the play and maybe ategorize the mistake. If you keep finding notes that say e.g. "chased straight w/3 suited" then those are the big leaks.

Quote Originally Posted by rmariani
I lost with AK to a set of 7s, with KJ to AJ (wich is normal but still hurts), and all kinds of strange things. I know I will not win all the hands I play, even if I do a carefull hand selection, but yesterday I might have lost 99% of the hands I played!
Ick. That's bad indeed. When you lose 30BB shut 'er down, take a walk, get a coffee, whatever. Come back later. You witnessed the snowball effect here.

>Is this variance aceptable or should I associate it with my lack of skill?
Acceptable. Note your gains still outweighed your losses for the last 5 days. For a beginner, that's just fine.
>It's normal to fold 30-40 hands in a row with the best one being Q8 unsuited?
No. But not everything that happens is normal.
>When I'm in a bad day should I stop and do something else or pursuit my losses?
See above.
>It's normal to have all your hands beaten on the river on a bad day? Could this be because I chased my losses a bit too much?
Snowball.