UPDATE - Great. I'm starting to fell more comfortable compared to yesterday. Faster and longer lines. And yes, I confirm the left hand collaborates better with tablet and I almost never use ctrl+Z
After a quick improvement at the start, in 4 days i didn't improved in months.
Then reading around I discovered that I drew in a uncomfortable way (I even have pain on my back and shoulders for this) and I had to move tablet on the table. Plus, as I suspected earlier, it seems that my left hand is better for the tablet, but earlier (like every time I do something new) I could not fell clearly which hand was better (On the tablet, I can make almost straight lines and control pressure with the right hand but I still can't control direction after months, with left hand I'm not yet used to draw with tablet but I can control direction)
I think it should take 4 days again But I don't fell the urge to learn as before, since I'm more curious to getting used to a new technique of drawing I just learn during last two months.