Ongoing Anterior Cruciate Injury

I'm 19. When i was about 9 years old i was playing football and kicked the ground as i went to kick the ball with my left foot, and was told I had damaged my anterior cruchet ligament by a physiotherapist.

I think the details of the injury were dumbed down for me at the time, given my age, all i was told was that i had a "stage one" ACL injury, in perspective, stage 2 and 3 injuries require knee reconstructions. I couldn't run for almost a year.

I was given rehabilitation exercises to do, which consisted of me lying on my stomach with a bag of rice strapped to my ankle, and slowly lifting my foot up to a vertical position, then back down again. I did this for a bit less than what the therapist reccommended, and as soon as i could run i stopped.
I was also given a cream "difflam", which i used the reccomended 3-6 times a day.

Ever since, my knee has never felt 100%, and more recently has began to get worse, as i took up more sports. For example: where i am sitting now, if i straighten my left knee out, i feel an enormous strain on the joint, and have to put my foot down after about 5 seconds.

In short, is there any kind of treatment short of a knee reconstruction that could make a difference, as in a game such as football (soccer), i am having alot of trouble using my left foot.

Any thoughts much appreciated!