Looking at your report a little more, I think you probably want to focus on Abilene (29, 24 and 15) and the ABC affiliate from Sweetwater (20 KTXS). That would give you the four majors (ABC, NBC, CBS, Fox) in more or less a single direction. But 20 at -13.5 NM is unrealistically weak at that height. You need to go higher, I would guess. Or use some heroic antennas like a stacked array.
http://www.kyes.com/antenna/stackluge.html http://www.ifwtech.co.uk/g3sek/stacking/stacking2.htm