Ok.I finally solved my issue, I think. First, let me say that the splitter idea did not work. This was because my roof antenna is funkier than I thought it was. It is not good with either VHF or UHF. It is good with CERTAIN channels, whether they're VHF or UHF. The reason I come to this conclusion is because ABC and CW are both VHF channels and my roof antenna gets an excellent signal with CW, but a very poor signal with ABC. So, my roof antenna has some issues and that's up to my maintenance workers at my building to fix, not me. Since that pathetic antenna has been up there for years, I'd doubt they'd do anything about it anytime soon.
So, what I did was ditch the splitter idea and used arxaw's idea on the barrel splice so I can move my indoor RCA flat antenna around. I finally got it at a good spot where all channels have great signal, except for My9 (of course there's always one channel that likes to misbehave). My9 gets a decent signal, so it seems ok, but God forbid I get the slightest bit of interference, I could possibly get a breakup or dropout. But from the few hours I've watched the channel, it seems to be ok. So, I think my issue has been solved, though who knows how things will turn out when the weather changes or if there's a lot of interferences around me.