Answer:

obsess

Answer	Crossword Clue
OBSESS	Focus on one topic
OBSESS	Preoccupy one's thoughts
OBSESS	Be unable to let something go

OBSESS	Fixate
OBSESS	Be too single-minded
OBSESS	Preoccupy
OBSESS	Become preoccupied
OBSESS	Go gaga (over)
OBSESS	Fixate (on)
OBSESS	More than just worry
OBSESS	Haunt

OBSESS	Think constantly (about)
OBSESS	Dwell constantly (on)
OBSESS	Get hung-up (on)
OBSESS	Have a one-track mind
OBSESS	Worry persistently
OBSESS	Preoccupy completely
OBSESS	Preoccupy to an extreme
OBSESS	Dwell (on)

OBSESS	Think too much (about)
OBSESS	Think constantly about something
OBSESS	Dominate the thoughts of
OBSESS	Fix (on)
OBSESS	Trouble persistently
OBSESS	Totally preoccupy
OBSESS	Control
OBSESS	Stew (over)

OBSESS	Preoccupy greatly
OBSESS	Preoccupy the thoughts of
OBSESS	Haunt.
OBSESS	Preoccupy.
OBSESS	Haunt the mind
OBSESS	Beset
OBSESS	Preoccupy abnormally
OBSESS	Preoccupy the mind of

OBSESS	Can't stop thinking about something
OBSESS	Take hold of, in a way
OBSESS	Dwell
OBSESS	Keep thinking about, with "on"
OBSESS	Have a fixation