your enclosure is WAY too small. Minimum.. very minimum should be a 75g tank which measures 48"x18" floor space. You also need a much higher basking temp.. do a google search for 'urowiki' and read everything you can. Your basking temps should be 120F surface temp(measuring with IR temp gun) and ambient needs to be 95F hot end 85F cool end... this just isnt possible to achieve in a small tank like your using now. You should also make sure you have the proper UVB bulbs as well.