Done with excuses!

First time poster here! short story about me if anyone is interested: I am 26 years old and weigh 280 pounds, I had chronic asthma growing up which made for 12 years of little to no exercise, and years of medical steroids that i was told destroyed my metabolism. I outgrew my asthma around age 15 and from then until now I used the "bad metabolism" excuse as to why i was overweight. I now work at a moving company and get quite a bit of exercise daily even thou some days are much more than others so for the last couple years ive used the " I work hard for a living i dont need to do extra work". I finally woke up last week and decided its time for a big change before its too late. I have committed to 2 miles a day for 30 weeks (right now it is more of a sprint/ walk/sprint/walk pace) and a goal of at least 80 pounds lost in that time frame. I have also made some major dietary cuts but am by no means starving myself. I bought the bodymedia fit yesterday and it is definitely a good motivator.


i do have a few questions thou...

The bodymedia fit registered that i did 30,000 steps today... i did run the 2 miles and i was on my feet for 10 hours but i was mostly stationary packing belongings, im assuming it registered my arm movements as steps is there a way to fix this because it showed a 5500 calorie burn today which as much as id like to believe it seems like a pretty high number.

also i am trying to find the fat burning heart rate range for me.. and i dont own a heart monitor but i was on a treadmill this morning, when i got on i waited 30 seconds of deep breaths at a stand still and registered as low as 98bpm.. when i punch this into my bodymedia fit heart rate calculator it comes up that my heart rate should be146 to 156( 60 to 70 percent ) but when i was running i would average between 178-188 sprinting and during the fast walk my heart rate was 145-160.... is there a reason for this or is it just because of me being overweight??
sorry for the long post but new to this and very interested. 4 days in and so far i already feel amazing