Do you think if I run three times a day, get up and walk around more during the day where I work, I could lose 20 pounds by the time I go out of country at the end of this month?
WhAt can I use as motivation?

For one thing I would say to not run three times a day. You will probably end up injuring yourself. Your best bet is to mix in some sort of strength/resistance training because that will burn way more calories and fat. You should also stick to a very strict diet because to lose weight your calorie intake must be less than what you burn or else you won't lose weight.
As far as staying motivated, I would keep a strict schedule of your workout routines and if possible workout with a friend, so that you can keep each other motivated.