NEED HELP WITH FORMULA: Status Based on Target End Date and Actual End Date

I have a status column that I would like to automatically update based on the dates in the Target End Date and Actual End Date columns. The parameters are as follows:

• If the Actual End Date is less than or equal to the Target End Date = Completed On Time
• If the Actual End Date is greater than than the Target End Date = Completed Late
• If there is no Target Start Date and no Actual End Date = Not Started
• If the Target Start Date is greater than today's date = Not Started
• If there is no Actual End Date, AND Target End Date is over 8 days away = On Track
• If there is no Actual End Date, AND Target End Date is less than 8 days away = At Risk
• If there is no Actual End Date, AND Target End Date is past today = Behind

This is the formula I've got so far. It's nearly there..

=IF(OR([Task Name]@row = "Initiative/Program Overview", Program@row = "Initiative/Program Overview"), "", IF(AND(ISBLANK([Actual End Date]@row), [Start Date]@row > TODAY()), "Not Started", IF(ISDATE([Actual End Date]@row), "Completed On Time", IF(AND([Target End Date]@row >= TODAY(8), ISBLANK([Actual End Date]@row)), "On Track", IF(AND([Target End Date]@row <= TODAY(8), [Target End Date]@row >= TODAY(), ISBLANK([Actual End Date]@row)), "At Risk", IF(AND([Target End Date]@row < TODAY(), ISBLANK([Actual End Date]@row)), "Behind", ""))))))

Most of this is working correctly except:

• Tasks that should be "Not Started" are showing as "Behind"
• I can't figure out the right formula for "Completed Late"

I would love a nudge to help get me over the finish line.