Your chest voice is coming along nicely but you tend to fall flat if you go into head voice and then return to it. Also you get breathy which means you need to develop your breath control. Practice taking a large (as you can) breath and exhaling it slowly. Visualize blowing it through a straw (you can put a straw in your mouth literally to do this) Count as you (1 Mississippi, 2 Mississippi) exhale. Repeat a few times. Each day try to get your "count" number larger. Your voice is very nice when you are on