Hi Angie
I do two 45min weight sessions Monday and Friday and then do 30 minute walks 3 days per week with 2 rest days.
45 x2 90minutes
3 X 30 90 minutes
Its easy to fit in during the week.
Even if you walk for 10 minutes three times a day it's exercise.
I feel a lot better since I started to exercise and have found the Lymphodema in my arm and chest is better since exercising.
You can get a health plan from your GP and one of the options is an exercise physiologist so that is an option to help you start exercising.
hope this helps