Yes, I suggest you speak to your dentist regarding the lump on your lip, and also request that they use non-latex gloves.
Regarding the ulcers, you can now get a special wax from some orthodontists which you put over the bases where they are causing irritation. Mine offered it to me three years back, but not all do. Mention that your brace is giving you bad ulcers and ask them what they can suggest.