Is the lumpiness on the bridge of my nose excess swelling, scar tissue, or bone that wasn’t removed? 6 months post-op (Photo)

I see the ridge and the divot. They appear to be there because your nose looks like the bones either were not narrowed, or perhaps they were, but they widened under the splint? I can also see the outlines of your two tip cartilages, and they look a little prominent, the tip wider than I'd like to see it, and the strong tip cartilages make the frontal and three-quarter views look long, as if the tip could be elevated at the same time as narrowing it. You didn't post a pure profile view, but strong remaining tip cartilages also often hold the tip out forward away from the face more than we like, and bringing the nose back closer to the face might be on a revision hoped-for list as well.
I'm not mentioning this to make you crazy about your nose! But whenever someone has a revision, it's important to at least evaluate *everything* that might be changed further, rather than just going in to take care of one item. Not all of these might be addressed, but they should at least be mentioned and evaluated, if they turn out to be important to you.
Morphs can help in figuring out what to do before surgery. In fact, I consider them mandatory before surgery.
Remember that rhinoplasty is an exquisitely difficult operation to get right, and you should only have surgery if you are able to make yourself very confident in your surgeon's skills. The changes that your nose needs require advanced techniques, requiring skill that most plastic surgeons don't possess with expertise. For most noses, it's much better to not have surgery than to have inexpertly-performed surgery. Read my essay on how to stay out of trouble while selecting a rhinoplasty surgeon. And for those who have had previous surgery, it also discusses how to tell whether your first surgeon should be performing your revision.
Your nose is also a perfect example of why computer imaging is mandatory in rhinoplasty. You need to know exactly what the surgeon is planning to accomplish -- what features he thinks he can change, and by how much he thinks he can change them. I always email morphs to my online rhinoplasty consultations. When you see the surgeon's goals in the morphs, you'll know whether he has an eye for an attractive nose, and whether he shares your opinion of what constitutes an attractive nose. You'll also know whether the changes he proposes are large enough to be meaningful to you, and whether he understands your wishes enough to address all of your priorities. How would you ever get that figured out without the morphs?

I can certainly see the bumpiness you are referring to. At 6 months you are half way through your final result. The bumpiness could be due to any of the factors you mentioned: swelling, scarring, or bone that wasn't rasped down or fractured in correctly. Most surgeons, including myself, would recommend you wait at least one year from surgery to consider any revisions.#RealDrWorldWide #StayBeautiful