Perfect Day for a Bananafish and TCITR

I'm not finding much of a connection between the characters of the Catcher in the Rye and a Perfect Day for a Bananafish. Perhaps Seymour Glass is like Holden, a little unsteady and unusual in the head. Maybe Sybil is like Holden's little sister? I'm not at all sure, though. I all but ripped the paper copy of the A.P.D.F.A.B. in half when I got to the end. My mom was disgusted when I told her; she, and I, were wondering why in the world we would read something like that.