I read your concerns and reviewed your photo. A mucocele usually presents as a bulge in the lower lip as a result of a blocked minor salivary gland. These may be managed by drainage, marsupialization, or excision. When a mucocele is excised, this may result in a localized loss of lip volume...
Your concerns are valid, as we have all seen terrible examples of overfilled lips on celebrities that are unflattering and look unreal. An expert lip enhancer will know just how much dermal filler is needed and where it should be placed. The mouth can be made to look a touch wider by injecting...
The only way to correct the current problem with lumps is using Hylenex. It might rake a few treatments to dissolve the filler. Infection would present with more swelling, redness, and tenderness.