Lets start with saying I thought I was prepared.......but I ended up being slightly under prepared

This morning I woke up and the tank was at 67 degrees... We rushed out and had to mix and match things and ended up with a dual mini lamp housing now currently with a 13w UVB bulb for light and a 25W blue bulb that I intend to keep on 24/7, I would like to replace the blue bulb with a CHE, what is an appropriate wattage for a reg 20x10 10 gallon glass tank? I am having a hard time keeping the temp up, I cant seem to get it over 74 degrees. so my thoughts are a CHE bulb might be better, all but one side has foil on it as well as the mesh lid. I do have a UTH on one of the sides.

I'll be getting the new CHE this weekend after I get paid, but would like to know what Watt to buy

Also I just got him on 10/14/17, I offered food twice but I think I need to just leave him alone for the rest of the week. When the time does come to to feed what is the best process?