I feel like I'm letting them down, so to, so to speak.
( I ( ( ( ( feel ( like ( I ( 'm ( ( ( ( ( letting them ) down ) , ) so ) to ) ) ) ) ) , ) ( so ( to speak ) ) ) . ) )
(ROOT (S (NP (PRP I)) (VP (VBP feel) (SBAR (IN like) (S (NP (PRP I)) (VP (VBP 'm) (VP (VP (VBG letting) (NP (PRP them)) (PRT (RP down))) (, ,) (ADVP (RB so)) (VP (TO to)))))) (, ,) (S (RB so) (VP (TO to) (VP (VB speak))))) (. .)))
It seems to me that I am disappointing them. 
( It ( ( ( seems ( to me ) ) ( that ( I ( am ( disappointing them ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ seems) (PP (TO to) (NP (PRP me))) (SBAR (IN that) (S (NP (PRP I)) (VP (VBP am) (ADJP (JJ disappointing) (NP (PRP them))))))) (. .)))