What does the quote "I am no better than the old lightning-struck chestnut-tree in Thornfield orchard… And what right would that ruin to have bid a budding woodbine cover its decay with freshness?" mean?

Rochester is comparing himself to the splintered tree and comparing Jane to a new plant. Note, the two co-exist and represent them both. Rochester is telling Jane that without her.... he cannot exist. His inability to go one without her is represented by the tree after it has been struck by lightening.