I did the first step! Today I told to my mum, remaining on the general, that sometimes I have the desire to talk to a psychologist. I didn't tell that it's about possible OCD, and neither that I really think that I should go soon. Just that maybe I'd like to go in future, and I asked if it would be ok for her. She said yes.
But now if I want to begin going I'll have to touch the topic again, more seriously. And to tell it also to my dad. But what scared me more was to introduce the topic. Don't know why I felt that today was the moment...but I did it.