Don't feel bad. Jumping is one of the hardest "easy" things to do in a game. It also what usually marks when someone can call themselves a programmer. Because you have to look at something from real life and mimic it.

When you Jump you put upward force on your body. The entire time gravity is working against that force, even when you are going up. What is happening is gravity is reducing that force amount until it becomes zero. That is the top of your jump. Then you fall back down. But what seems to be missed is that at the start of your jump you are moving the fastest. At the end of your jump when you hit the ground you move the fastest. So for once instance at the height of that jump, from when you go from moving up to moving down, you are motionless, suspended in air.