I've encountered (in songs, mostly) the phrase "I love you so". I understand what it means, but I can't make grammatical sense of it. It's very different in meaning from "I think so" or "I told you so".
Is it a contraction of "I love you so much"? Is it the other way around?
Can the construction be used with other verbs, and in which context and register? I've only seen it with the verb to love.