Hi, It's possible you're taking the wrong dose of Becotide. I'm on Seretide for asthma and I can take different doses - ie 500 at present as have an infection but will go down to 250 when recovered).
As nights are worse, sometimes I take 500 at night & 250 in the morning - respiratory nurses say so.
Important to take it properly (I was taking it wrongly for three years before I was put right). Lots of clips on YouTube for all inhalers. Plus using a spacer is very beneficial.
Imy astma was diagnosed ten years ago although I realise now that I had it as a small child and throughout life when attempting to climb hills. It suddenly worsened in my forties.
As Knitter says, Buteyko is said to work, clips on YouTube.
Whilst I don't advocate taking drugs without seeing a doctor I sort of understand. I've lived abroad a lot and it was better to trust my knowledge rather than a local doctor.
My son was px Becotide and Theophillin at three. When we saw a gp in UK she was horrified and said it was taking a sledgehammer to crack a nut.
It's vital to avoid pollution, diesel fumes, chemicals, extreme temperatures, damp, smoke, mould etc etc.
If I were you I'd get a private allergy test done. Skin pricks. See what you're allergic to for starters. Mine was mould and slightly aspergillis (another mould).
Also, take your Ventolin before exertion. The trouble starts when your airways are compromised for whatever reason and mucus cannot escape leaving a perfect environment for bacteria so then the serious chest infections start - these can damage your lungs if not treated properly.
At the slightest sign of infection do see your doc.
Are you in the UK?
Good luck. P