TMZ Reports Former NFL star Bob Whitfield has 21 days to fork over $75,000 to his reality star ex-wife Sheree Whitfield for overdue child support … or else. According to legal docs obtained by TMZ … Bob admits he failed to make 38 monthly child support payments of $2,142 to the “Real Housewives of Atlanta” star … more than $81k. Bob claimed he simply didn’t have the money — and had asked the court to lower his obligation … but that was denied. Now, the two sides have struck a deal in which Bob has agreed to hand over $75k before Nov. 11 … or face the consequences in court.…