Rehabilitarme means "to rehabilitate myself." It's an interesting word choice because it's typically associated with recovery from addiction or injury, not heartbreak.
In this song, the singer uses it metaphorically to describe his desperate need to overcome his addiction to his ex-partner's body. He's so consumed by his feelings that he feels he needs
"Ayudame" is a breakup song that treats heartbreak like an addiction. The singer compares getting over an ex to going through therapy: he's stuck in denial, new to depression, and can't stop wanting to kiss her even though the relationship is over.
The chorus leans into dark humor, common in regional Mexican music. He jokes that his therapist is tired of hearing the same story, and that the promise of "together forever" fell apart. He'd rather she hang up on him if he calls drunk, or tell him to get lost if he begs her to come back, because he doesn't trust himself to stay away otherwise.
By the end, he compares his feelings for her to a physical addiction he wants to recover from, admitting he can't do it alone, which is exactly why the song is called "Help me."