Elisea, slow down, honey! Here in the beginning you do not want to have to get up from low surfaces.
And I never used anything but a walker. I used it for 3 weeks. When I had my hip replaced I used it for 6 weeks because I wasn't allowed to fully weight bear for that period of time. There is not a set time frame for any of this. You do what you need to do for you.
What you NEED to do is take your pain meds on a schedule, get LOTS of rest, elevate (toes above nose), and ice, ice, ice. Just gentle stretching and bending--ankle pumps, straight leg raises, heel slides--off and on during the day and night.
And, of course, take and eat whatever you need to to stave off the dreaded constipation monster that comes with the pain meds.
This recovery is going to take you as long as it takes you. That's the way it works. You do what your knees will allow you to do, and you do those things carefully. This is not a competition--it doesn't really matter when someone else was able to do anything---it's all about YOU and only YOU and what YOU can do when YOU can do it.
You are going to be fine----but not today or tomorrow and maybe not next week or the week after, but YOU ARE GOING TO GET THERE! So chill, baby, chill!
Take care of yourself, chill out, keep us posted. We care!