Hello All - New to this EOY crunch to get segments on US Air.

When I look for fares between cities, I find cheap fares. When I try to put them together, the prices go way up.

Can I buy each fare separetly for the same day while still getting credit for the segments?

For example -5 separet tickets for same day travel.
tpa to bna;
bna to pit;
pit to bna;
bna to atl;
atl to tpa