Leenia, just start using the capo on 2-chord songs in keys that work for you. Once your mind makes the connections, which it will do automatically after just a few practices that feel awkward, the problem you have in using it will vanish.

Think not, "I can't do this because..." and instead try thinking, "How I can make this work for me is...."

This approach also will work in trying new chords. Soon you will own them.

~S~