How Can Swelling And Pain In The Knee Be Treated?

I am a 64 year old female. I have had jobs that require being on my feet for 8-12 hours a day on cement floors. I carry some extra weight 20-25 lbs. I was kicked in the knee by a horse when I was a child. I fell very hard on a cement floor with my knees taking the brunt of the fall 2-3 years ago. About 18 months ago I began to suddenly have pain in my left knee. Getting home from work and getting off my feet helped some but by mid day the following day it was again painful. Later that summer I jumped out of a boat onto a hillside and , my knee popped twice and I was in extreme pain. I would ice my knee to take down the swelling but was still working. Tried an assortment of knee braces and topical treatments. I take Mobic/Meloxicam for fibromyalga and can not take any other pain relief besides tylenol. In January I had x-rays, MRI, and was referred to Ortho. I was told I have a torn meniscus, Ostoarthritis and a degeneration of the knee cap. I was told surgery was not an option. I was told cortizone shots was my only option. I have always been very active and because of knee pain, I have had to limit my activities. I am fine w/o pain if I pace myself but always over do it and then end up with a swollen knee and can t get around for a couple of days. I am wanting to fix this and not cover up the pain with cortizone. The thing that bothers me the most is if I sit for any length of time I have trouble straightening my knee. It is like it locks up. This also causes me pain until I can get it straightened out and be able to walk on it. My question is are there any other options ? Thank you for your time.