Hi Will ,thank you for the answer :)
I was thinking that the direct sun light is bad for it. Actually this bad period started when the sun appeared late march beggining of april. It might be also the soil not dried out even dough I dont think I over water it. Putting around 300ml eveey 7-9 days. The surface of the soil is almost always dry. Could it be also something with the pot, not be able to breath properly or not enough air going in maybe, which is the couse of the not dried soil ?!? Dont know , but I really want to mentain flowers home and it is making me feel bad when I cant do it. And sometimes it is a very small change , that can make anhuge damage on the plant :)