I agree with Swanhunter: if you are SERIOUSLY scared of flying, look at one of those "fear of flying" courses. The course will take you on a short "flight to nowehere" from your local airport. This is a good idea because it allows you to face your fears before you actually have to go somewhere.
As others have said, flying really is very safe: safer than getting into a car or crossing the street or even going fishing (no joke, apparently fisherman, long carbon fibre fishing rods and overhead power lines don't go very well....

). Both the 747 and 777 are great planes AND BA has a VERY good safety and maintenance record.
There are never any certainties in life, but one thing is for certain - flying opens up the some amazing opportunities for you
Hope that you get this sorted out and happy travelling
Boo