At least 8 ounces a day is recommended. If you are an active person, I suggest more since you will be needing more replenishment then a average person who is not active.
You a to do your research. Find out what types of clothes would look better for your size and what designers make the type of clothes you are looking for.
You should just take your scale and put it in your closet. Take it out once a week, preferably in the morning. Funny thing that other people will notice that you are losing weight before you will really can tell.
There are lots of exercises that can be done if you are suffering from osteoarthritis. You just have to figure out what you can do. Non load bearing exercises. Like swimming and stationary bike for example...