Too old maybe.. Uvb fades out w time. I usually switch mine out every 6 months. Getting a Mercury Vapor bulb/reflector kit so I can save some cash in long run
Some other diet items you could try.. Yellow squash, zucchini, apples, carrots, sweet potatos, I usually shred or dice aforementioned items. Protein could be soaked dogfood & soaked dog biscuits.