Replaced shower faucet and now water isn't warm...Help!

Last week I had the Shower retiled and the cast-iron tub epoxied and resealed. One part of the job was replacing the old double handle faucet to a new sleek single handle faucet. I had to wait 3 days for the tub to cure, so when I went to shower today in my newly remodeled tub you can imagine my surprise when the water was lukewarm at best. I am pretty handy and went to the basement to check the hot and cold feed pipes, and even with turning the cold feed to almost nothing, the water temp was still not hot. I checked the HWT and the setting was on high. Also, I would like to note that with the old two handles, you had to turn the hot numerous times and only turn the cold on slightly to get the perfect temp. Does anyone have any suggestions on what else I can do in order to get the perfect water temp?

Thanks,
Girl-DIY :thumbsup: