Just to anybody who has followed or has an inetesr in this thread........I passed my medical this morning.
The Dr had a quick check in his book about drugs and it said that you can use ventolin as long as it is just for occasional use as long as you are flying "heavies". He said that they don't mind about asthma as long as it is not going to affect you in the cockpit. didn't go into what would happen if it gets worse.
He made me do a peak flow test which he said was quite good. Practising it helps. (Thanks for the link skygazer)
If anybody wants to drop me an e-mail for further reassurance, the contact me through this forum.