Talk to General Physician on Breathing Problem

I am asthema patient(seasonal mostly in winters)when i felt this i always take mytica 10mg and Combivaior 400.it dosen't occures in summer.but now since April i have shortness of breath mostly it starts in evening and when i lay down feel like something stuck in my throat but during sleep i feel nothing.when i take complete rest i will be fine.i have no fever no cough no soar throat no headace no body pains etc.but in winters i can listen wheezing sound and also had cough but now no wheezing and no cough.i got a chest x ray two days before i went to doctor he said its ok as already mentioned on the teport that both lungs are clear.now plz guide me abiut this.