Green’s Dictionary of Slang

to bother, as in all sheg up, all hot and bothered, or all spoiled, as of work that has been ruined.

1971		T. Rhone Smile Orange Act II: You sheg up everything, man!
1995		Francis-Jackson Official Dancehall Dict. 47: Sheg-up [...] 2. to make a mess of: u. ’im sheg-up de plan.