Will more filler worsen the appearance of these bumps? (Photo)

I recommend getting a formal consultation to discuss your options. If necessary, the filler can be reversed with hyaluronidase. I hope this helps. 

Thank you for posting this question and providing the picture.  Since it is more than a month since you received your injections the lumps are probably the Juvederm Ultra Plus and not bruises that could be expected to resolve on their own.  I don't think that adding more filler is the best way to address this, because if it is placed as superficially as the lumps are, the filler will only create additional lumps.  If the lumps are due to uneven distribution it may be difficult to just place it selectively and get a smooth contour.  Your lips are also likely to be larger and look unnatural.   It would be much safer and more effective to have the lumps treated with injections of Hyaluronidase to dissolve the Juvederm (it may take more than one session to remove the lumps and the initial Juvederm completely) and then follow-up with new Juvederm no sooner than a week or two later.