I dont know why but I have started having feelings that Jay would be the man behind Zoom. Following are my observations:
1. Why Jay powers were lost when he arrived at Earth1, on the other hand Zoom and other meta-humans powers were intact. Jay is lying that his powers are lost so that no one will ever think that he might be Zoom. The same thing which was done by Eoward Thawne in Season 1 when he turned into Dr. Wells and always sat on wheel chair.
2. When Flash team decided to fight with Zoom, Jay clearly declined the decision and left the team. If he was a superhero, he would have never left the fight like a coward. He left because he is Zoom.