That's OK. Dumbells are still probably the most versatile pieces of exercise equipment there are.

Along with the suggestions already made (weight on shoulder, single leg work, especially the single-legged split squat), I'd add more lunges, walking lunges, etc. High step ups onto a bench. Perhaps sumo squats if holding the same amount of weight but two-handed with a single dumbell is more comfortable to your shoulders. Perhaps sissy squats with bodyweight. When/If you outgrow all of those, then you might be ready to attempt pistol squats with body weight only.

You might also try doing your regular squats with a slower temp on the concentric and increasing the pause at the bottom. This might increase the challenge for you without increasing the weight.

THanks Depalma. I am going to make a list of all these great suggestions and try shaking things up and incorporating some new things.