The knocking sound gets louder the faster I go. If I speed up the sound speeds up when I slow down it slows too. The sound will stop when I accelerate up a hill and also when I apply the breaks more than half way down. I can feel the clunking in my feet and sometimes the steering wheel vibrates with the sound. Before the sound started I was told by a shop that the ball joint was going, could that be the problem? Additionally the inside of the front driver's side tire is wearing down faster then the rest of the tire.
The shop diagnosis makes sense with your symptoms, and this is a dangerous issue if true. It is possible that the ball joint is worn enough to allow the wheel to contact the tie rod or other steering or suspension components - very dangerous.
Noise increases with road speed, thunking is transmitted from the wheel to the chassis itself, inside tire wire. All of these point to a worn ball joint that has allowed the tire/wheel out of normal position to the point of contacting other components. Balls joints can, and do, fail, allowing the suspension to collapse instantaneously.
I would recommend having the clunking or knocking noise inspected by a mobile, professional mechanic, such as one from YourMechanic ASAP, to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.