My left side scrotum swells up big and it looks ugly like its filled with some worms when I sleep it comes to normal.... I have no pain when it swells?

Get evaluation. This could be different things. If it looks like worms, it could be varicose veins associated with the vessels going to the testicle (Called a Varicocele). It could also be a hernia or other abdominal wall problem. Best to be evaluated by a surgeon or urologist. This may require an ultrasound to make the correct diagnosis.
Scrotal swelling. You are describing a varicocoele it is benign. But can result in fertility problem.