Like Candy had said, you need to provide your glider a well balanced diet. Below is a link that list several of the approved diets that have kept glider healthy for a good number of years:
www.sugarglider.com/gliderpedia/index.asp?Diet
The BML is good because the ingredients are easy to get. The HPW is easy to prepare since it comes all packed up, you just need to add water (if you buy HPW Plus) or some bee pollen and honey (if you buy the HPW Complete), but you need to wait for it to be shipped. Candy's diet plan is another good option.
It is up to you what you choose to feed. Just keep in mind that with diets is necessary for you to follow the instructions provided, because the people that came up with these diets did it so gliders would get the exact amount of nutrients they need; and when you change things around so does the nutritional values.
All the things you are currently feeding are approved things gliders can eat, but in moderation. Mealies and yogurt drops are usually treats (except in the BML where they are part of the diet itself), feeding too many of these can make your suggie fat, and then create other health issues.
Hope this is helpful.