How can I have a really clean room?

Find a home for everything in your room and try to have it realistically organized to fit you. It's okay for it to get messy during the day as long as at night, before you go to bed, you take time to pick your room up. If there's things in there that don't belong, don't go around your place trying to place it in its home. That might overwhelm you. Just have a designated catch all basket. Another day when you have time, pick up the catch all basket and go around your house placing everything in the basket back into their homes.