Can I say a huge thank you to those who have taken the time to respond to my post. I think everything you're saying is valid and confirms what my friends have already told me, the exception being that they aren't as positive as you guys. They've seen me fail so often that it's a case of "we'll believe it when we see it". I think I'll take RunbikeSki's advice and try to take a month's unpaid leave from work to give me the time to kick-start my new healthy approach to life, at least I can get a weekly menu set up and cook batches of food to freeze, start some form of exercise, etc. The good thing about a site like this is the feedback you get from people who are in a similar situation (or have been in the past) and can give you advice based on their own experiences. For this reason I'd be so stupid to ignore the fact that the overwhelming consensus is to NOT give up my job!! Now that I've found this forum I shall use it regularly and post my progress on a monthly basis. I don't want to weigh myself more often than that as I'll get too obsessive!!!
Once again, many many thanks to you all for responding.
Starting Weight: 240lbs
Starting BMI: 45.3
Height: 5' 1"
Goal Weight: 140lbs