Recomenzar means 'to restart' or 'to begin again'. It's a less common verb than simply 'comenzar' (to begin), adding a nuance of starting over after a pause or difficulty.
In
"Yo Te Amo" is Chayanne's plainest possible love letter. He opens by saying he doesn't need fancy words - simple language is enough to say he misses someone and that they are his whole world.
The song is really about total, unguarded devotion. He promises to grow through love rather than fear losing it, and pictures himself as a shelter: "look at my chest, I leave it open, so that you live in it."
By the end he drops any hesitation completely, singing "I belong to you, all of me." It's a song about choosing someone fully, without holding anything back.