" ... hurts a lot when i try lifting my leg up "???
As in when your not training when you try to lift your leg you experience pain? If this is the case then it sounds like you've injured yourself and should ease up a bit. If it persists then you need to go see a Physiotherapist and get yourself checked out.
If this isn't what you mean then I agree with ninjaboy, your problem could also be flexibility:
Try looking at the warm up you do (I'd normally do around 5 mins of dynamic stretching and 10 mins on a rowing machine at about 20 SPM).
Drop back on the weight you're lifting when doing the Squat and concentrate on your technique (plenty of good articles available on this site explaining how they should be done)
If you can't find a trainer get a camera and record yourself so you can critique your performance.
Lift heavy and deep using a machine. this way your body can get used to the range of motion you have to do
Also a good cool down incorporating static stretching