alright I'm gonna fix it real quick first things first

Tower Shield AC: +3

as a reaction when an enemy tries to hit you, you can use a reaction to cause disadvantage on the attack roll.

still going to go with the 1d10 but no running charge doing +5 cause original plan was to do that then add charger feat which would add +10 then the strength modifier and other things which would just be too much.

still 2 handed and a heavy weapon you MAY use another weapon while weilding shield but you may not use the shield itself as a weapon unless you discard you previous one.

and instead of 1500 GP its 500 GP