That sounds a bit low which may be affecting his appetite and health. For a baby, I suggest having a basking area between about 100-110 with some areas around that in the 90s. The cool side of the tank should be around 75-80 or so during the day. There should also be a source of
UVB light over the basking area. It's important to get accurate temperature readings using an IR temp gun or a digital thermometer with a probe. You can adjust the temperatures by raising/lowering the basking light or the basking site depending on what your setup will allow for. I've found it helpful to use an adjustable lamp stand to raise/lower the basking light to get the correct temps, or to use a lamp dimmer to control the output of the bulb.