Don't worry OP, it takes a while to get the knack for it, especially if it doesn't come naturally to you. I was, (and am) still shit at driving, and I've had years of experience.
I passed my test first time, but, I think tests now are harder, especially if you have to take it in a busy city. You will get the hang of it, just keep doing it, that's the key, you must keep doing it, again and again and again.
My instructor told me to stop thinking of it a driving a car, but to think of the car as an extension of myself, so the tyres were my feet, and I wasn't "parking a car", I was just "parking". I wasn't "driving a car through a junction", I was "going through a junction". Somehow this helped me focus on the road more than the car and my body just sort of stopped panicking.
Keep at it, just keep at it, it will come together.