Sorry to hear of your troubles with your knee. An ACL that is stretched, but intact will show up as an intact ACL on an MRI. If you are having ongoing problems of instability, you need to find an OS that will go by the results of the physical exam with your knee(which it seems you have found). Those test do not usually produce false positives. Your ACL will not shrink back. You can work on building up your quads, but if you are still experiencing difficulty with instability after this, then you need to seek other alternatives. If your latest OS states that you have a stretched ACL, and your knee has ongoing issues of laxity, then obviously there is a problem.
If I were you, I would spend your energy in trying to get your problems resolved, so you can get your life back. You cannot change what has already occurred. Get your knee problems resolved first. If you are still feeling the same way later, then you can always see if you have a case.