Have you done goblet squats? The goblet squat is an excellent exercise that is much easier on your body than using a bar.
Holding the dumbbell in front of you (like holding a goblet) helps to balance you while you sit to the bottom of the squat.
Another benefit of the goblet squat is the shoulders are not put into external rotation (as in having a barbell on your back) which spares rotator cuffs while still being able to do squats!!