Chronic bronchitis.

So I have asthma and chronic bronchitis. For the last few years I've got bronchitis every time the weather changes from season to season. Well my ob prescribed me singulair to help with asthma and allergies. This has worked great and I haven't been sick like I used to. Well I had a change of insurance and they keep putting prior authorization holds on all my important medicines like advair and my singulair. I haven't had my singulair in atleast 3 weeks and now the fall is coming and temps are dropping I feel a cough coming on. Is there anything that I can take to try and prevent this any teas or medicines until I get my prescriptions?