Hi Radoslaw,
I am not an expert. First, your shop looks ok with nice, clear photographs. Also,, very cute items.
But, don't forget, that etsy now has over 4 million shops with everything you can imagine. It takes time and patience to find customers.
Joining a team is a good idea. And, posting your questions in the forums can help, too.
And, why not talk about your items to people outside your etsy shop.
Right now, many of us have slow sales. Could be the overall economic situation and, unfortunately, for you the higher European shipping cost.
But, hang' in there and be persistent.
Elisabeth Shaffer