Sounds like you should abandon any attempt to change the way you walk. Normal walking is with the foot slightly turned out as you land on it so trying to make it dead straight is incorrect and would lead to issues. If you have balance issues then go see someone to assist assess why you have balance issues. When this does occur the feet often turn more outward to increased the side to side balance. There may be much more to understand here and altering your walking does not seem to be the best starting place.