Default [Q] sd card occupyed

sorry for my bad english!i own a xperia p and my sd card is more occupyed than it really is...when i look in settings> storage it says that i have 5 gb avalaible from 11 but when i connect my phone to pc and check how much memory is occupyed it says 2.4 gb ... all beggined i think when i restore my data with cwm after i get installation aborted from cm11(i think i dindn't have to do that)... after a new failing of rom installation i did another restore. i tried to format my sd card from settings>storage>format sd card but nothing happened :-l . i use now cm11 based on beanstalk 4.4.2,and i have to say that i can't enter in cwm...please help me!what do i have to do to have all my memory ?