You're Not Storing Your Onions Properly
You need to keep your onions and garlic far away from sunlight and any kind of moisture. It's important to keep them dry and cool so they don't develop any mold and they retain their flavor.
You're Not Using a Meat Thermometer
Cutting open a piece of meat to look inside of it is the absolute last thing that you want to do when it comes to determining whether it's ready or not. Get yourself a meat thermometer, and learn up on how/where to prod a cut to get an accurate read. Don't ruin your chicken by slicing off the breast while it's still raw.