I've been spending all my salary and have got to find a way to keep my expenses in check.
Usage notes: often used in the form hold something in check:
Sometimes it's hard to hold your emotions in check.
in check
Under control; contained or restrained. You've got to find a way to keep the company's expenses in check, or you could end up going bankrupt.He was careful to keep his displeasure in check as he unwrapped the present from his wife.
in check
Restrained from moving or acting; under control. For example, The first division held the enemy in check, or Mary kept her emotions in check. This term replaced at check and out of check, which date from the mid-1500s.