Hey PacoPaco
I have to tell you that I only had a two year relationship and mine ended a year ago in January. The length of my relationship was not even half as long as yours and I am still very sad. Actually I am feeling severely sad for a few days already and it feels so intense as if we just broke up a week ago. The difference though is that I still have a lot of contact with my ex and I think that is why I am in the stage I am. I still did not give up hope for us to come back together and as much as I wish I could move on, inside of me there is always something that keeps me hanging on to my ex.
I already started some therapy but not even that seems to help. I always have set backs.
Paco, I really think that it is ok that you still have these feelings. People are different and that is why some take longer to let go of someone they deeply love.