 He found himself thinking in circles of worry and pulled himself back to his problem.
( He ( ( ( ( ( found himself ) ( thinking ( in ( circles ( of worry ) ) ) ) ) and ) ( ( ( pulled himself ) back ) ( to ( his problem ) ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VP (VBD found) (NP (PRP himself)) (S (VP (VBG thinking) (PP (IN in) (NP (NP (NNS circles)) (PP (IN of) (NP (NN worry)))))))) (CC and) (VP (VBD pulled) (NP (PRP himself)) (PRT (RP back)) (PP (TO to) (NP (PRP$ his) (NN problem))))) (. .)))
He got lost in circles of worry, and could not face his problem anymore.
( He ( ( ( ( ( got ( lost ( in ( circles ( of worry ) ) ) ) ) , ) and ) ( ( could not ) ( ( face ( his problem ) ) anymore ) ) ) . ) )
(ROOT (S (NP (PRP He)) (VP (VP (VBD got) (VP (VBN lost) (PP (IN in) (NP (NP (NNS circles)) (PP (IN of) (NP (NN worry))))))) (, ,) (CC and) (VP (MD could) (RB not) (VP (VB face) (NP (PRP$ his) (NN problem)) (ADVP (RB anymore))))) (. .)))