im at the 20 week post op stage now after ACLr with hamstring. I also had no brace and no CPM. Seems to be the normal protocol here in UK. You are still in the very early stages of the recovery process. Dont try and rush the recovery. There is no quick way around it. I know what you mean when you say you feel unstable when trying to walk with normal walking pattern. I was the same as in i felt unstable as if my knee would hyperextend after id stopped using crutches at the 10 day point. Just be very careful on all surfaces you walk on and where you plant your foot. All the muscles, particularily the quads will be very weak and unable to help support the knee like they should normally. Just stick to the ROM particularily regaining the full extension if you want to loose the limp, and strengthening activities and you WILL see steady improvment in time.
All it takes for swelling and pain to return is a small over stretch or slip etc and the joint could be aggravated. Happened to me twice but as the leg muscles returned, i had more control over my knee and gradually the swelling dissappeared and didnt return
As i said im at 20 weeks now and running regular with no problems or pain including interval sprints, jumping and rebounding exercises, one legged hoping and rebounding. I saw big improvement after the 9 to 10 week mark in terms of agility, strength, balance and muscle mass in my quads building quicker
Good luck with the recovery