What would cause me to be unable to stand up and walk freely?

For the past two months I have been steadily losing my ability to walk normally. I am scared. My doctor says once I get insurance she will run tests like MRI or CAT SCAN. Well in the meanwhile I was wondering if anyone out there has had this happen to them and what was wrong. It happened rather suddenly. I have had arthritis and diabetes for three years but this is a muscle thing. My muscles are in pain and weak. My family says if I use a walker or stick I will just get worse but I really have trouble balancing. They are in denial so I am appealing to you for consolation.