Help with mechanics: TREXing/ no rotation, arm/leg action

I need help with a problem that has been diagnosed as TREXing. Being that my arms go straight back and forward (respectively between the two arms). The overall implication of me moving my throwing arm back straight back to second base and then straight forward to home is that I lose alot of rotational velocity. Also I have the problem of not properly using my lower body; I tend to over sync my upper body with my lower body, being that as my arms trex, my legs also make a v-shape. It looks like I am doing a jumping jack as I throw.
Any comments or help with my mechanics will be appreciated, and I hope to have a video up soon. Thanks!

Arms going straight back and forward isn’t necessarily a problem. Syncing the upper and lower halfs such that hips and shoulders rotate together is a problem. My suspicion is that your glove arm is affecting your timing. But we really need to see some video.