One of my friends I normally record also has a bassier voice, and a similar problem. It is good that you acknowledge that it sounds dead, because when performing, you can not hear it the same as someone listening would.
You can use EQ to assist in this problem by working on the lower frequencies. But, honestly, you have to fix the source - yourself. One thing I would suggest is to practice your inflections. How does the
tone of your voice change as a verse progresses? Are you performing your verse with excitement, or emotion? Is high energy conveyed more than the actual meaning of the content?
This may sound unorthodox, but this is something that I have practiced with
theatre professionals. Take any one of your verses, someone else's verse, or, even a Dr. Seuss book. Choose a word that has strong feelings associated with it such as hope, despair, disgust, or ecstasy. Read the entire piece as if you were trying to convey that word, even if is not associated with the text. Do this over with different words.
Also, it would help to describe your setup. Maybe it's just your mic and my advice is unnecessary. Please go into further detail and let me know if this helps, I can also offer more advice contingent on your situation.