The majority of swelling if not all should have subsided at this point. Schedule an appointment with your injector to discuss your options. If you are unhappy, having the product dissolved may be your best option. It is common for lips to have a slight increase / decrease in water retention.
Please see your injector for a physical examination of your lips. Hyaluronidase may help, but this could be caused by something else.
While Volbella is not currently an FDA approved filler in the U.S., it is still a hyaluronic acid filler which can be dissolved. Since the nodules are new and have not been there all along, it would be best to see your injector for an in-person evaluation to determine what has caused the nodules - the filler itself, some type of reaction or infection?, or something else.
"This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."
Thank you for your question. Since it has been 3 months already, I would suggest seeing your provider for further evaluation. Good Luck.