Well, "a bitter guy" would make sense and it does sort of sound like that's what Kenny L sings.
But the 3rd rhyming line in that verse ends with "I was a sorry guy." Usually songwriters don't use the same word twice in the same verse in that manner (using the same word instead of a rhyming word), so I doubt that "bitter guy" is the real lyric.

As to "beta chi" being a fraternity, that still is indecipherable to me.

G