Exercise Plan

Let me see:
I am a diabetic who is overweight, has PCOS, high blood pressure,and high cholesterol.  I also suffer from pain.  I am not sure if it is aging or weight gain.  I have no idea but I know that as I age, things have worsened.  I feel like my health has worsened over the years and I want and need to lose weight. I plan to lose over 100 lbs, which would not only lessen the pain, but would also alleviate or reverse the other symptoms.  That would be nice.  Sadly, walking is the only exercise that I know of to do, yet I am afraid of falling due to the arthritis.  I want to lose weight so I just have to count my losses so the speak.  My goals, specifically, are not just to lose weight but to keep it off.  My goal also is to lose 0.5-2.0 lbs per week, so that means that I would like to lose at least 5-10 pounds per month. I realize that I would have to change up on my healthy eating and exercise routine.  My goal for now is to walk for 10-15 minutes per day for four days per week.  I know it seems lazy and a low goal, but I realize and know that goals change overtime.  So far, that would mean that I would have to exercise, namely walk, 40-60 minutes per week.  I wish that I could walk or exercise for longer distances and more reps.  I have been to physical therapy twice and I feel so self-conscious about my weight.  I have been eating mindlessly. That is also something that I need to take care of.  My goal is to exercise for now only on Mondays, Wednesdays, Fridays, and Saturdays.  I guess I have no good reason for why I chose those days except for the fact that I need some rest, or at least my body needs some rest.  Maybe I should make a plan or a table on what to do.