The stretching and light weights is probably some of the best things that you can do. I am not sure but you spoke of isolation exercises. Is that isometric ex. if it is you may want to lay off those for a little while longer.
I know at this point you are getting frustrated, but hang in there. YOU SOUND LIKE YOU ARE GETTING BETTER. 6mos is long but you were really pushing on your injured leg.
glad to hear that you are doign better and that your surgery is scheduled.
OPI