MBD takes a while to develop and it takes a while to go away too. At least a month in the best of cases, and maybe longer if it's more severe. It looks like your guy doesn't have a lot of bone bending or fractures yet, which is good! He is skinny and looks dehydrated though. Make sure he is drinking a lot. Silkworms will be great for him. You should see an improvement in his symptoms in a few weeks if his MBD isn't too advanced. Make sure you are gutloading properly - calcium dust on the food isn't enough, it needs to be in his food as well. Feed your crickets collard greens, dandelions, mustard greens, and turnip greens (you can alternate those) at least a few hours before feeding them to him for better calcium content in his crickets. Gutloading well, calcium lightly dusted on his crickets, and a fresh UVB bulb every 6 months are lifelong requirements. So even when he is back to normal you must continue with these things or it will happen again. UVB bulbs stop emitting UVB after about 6 months of use, even though they are still shining so you need to replace it twice a year.