Shower hot water moving into cold water supply line.

[CincinnatiKid]

background- Insufficient hot water coming through shower head (already removed restrictor). It is a Home Depot Glacier Bay one handle valve. The valve has a hot water inlet and a cold water inlet and an up outlet for a shower and a down outlet, which is plugged, for a tub I assume. Removed integral water stops from both the cold wand hot water inlets. And now have great pressure but the water is limited to warm and hot and can't just get cold water. I also now have noticed that the cold water supply pipe is getting hot after the water has been shut off. Checking the cold water supply pipes to the nearby sink, toilet, and even the sink to the adjoining bathroom I find the pipes are getting hot. Even when water hasn't been run through them for hours. What have I done???? and how can I remedy this?
Thank you from this first time hoster.

 

[fixer]

Check your installation. Looking at the diagram, you most likely have it installed, rotated 90° off.