It's obviously Eddie. Why do you think they showed his body fly into the wormhole in S1?
He loved Iris, didn't really like Barry, showed up as a Time Remnant this season. It makes sense
My problem with it being Eddie is...fukk is he so mad about to be trying to kill Iris and Barry?
I mean nobody made him shoot himself. And if he's doing all this because he's mad that Barry and Iris hooked up
Just don't know if they could write a believable motive for Eddie to be doing all this.