Sounds a lot like when I tore my ACL. Pain went away in a couple days and I stopped thinking about it. Went to the orthopedist four years later. One of the first things he said was most young guys (I was one once) in my position only make it three years. It did not heal, you have just been relying on collateral strength in other places.
Nearly all ACL injuries can be handled with just a few simple exercises. Don’t fake it on your own. Go to the doctor, go to the physical therapist. If your doctor is a surgery-only doctor get another doctor. The docs who don’t do surgery at all are called sports orthopedists. That’s a board certified title. They know better than anyone who really does have to have surgery because they lose real fast when they attempt to treat someone with physical therapy when that patient really did require the knife.
Skiers and other competitors use physical therapy for ACL because they are back in training and back in competition far quicker than after surgery. Thirty years later I have to remember to do my exercises for a couple days about twice a year. My nephew who was a World Cup skier blew out both knees more than once and is therapy only, same as all the guys he used to race.