Shakes very bad when I press brakes

Your description can be due to a couple of different things. The most common on any car is warped brake rotors. Those can be machined as long as they are still above the legal minimum thickness. If they're worn too far, new rotors aren't very expensive. Machining is a standard part of any brake job.

If there's some other kind of shaking or vibration when you're not applying the brakes, it can still be due to the rotors but more commonly steering or suspension parts are worn allowing a wheel to bounce around instead of holding in proper alignment. You'll see uneven tire wear too. Ford has had more steering component problems over the years than any other manufacturer so it is time for an inspection at a tire and alignment shop. Never ignore these warning signs of trouble because if a ball joint or tie rod end separates, you don't know which way the car will go; into a tree or into a oncoming traffic.