Do this anulom vilom (pranayam) morning and evening, and you will not need anything at night.Come back with your feedback so others can benefit.
Build up your timing gradually.If you feel tired or dizzy, stop and resume after one minute.
Anulom Vilom –
Close your right nostril with thumb and deep breath-in through left nostril
then – close left nostril with two middle fingers and breath-out through right nostril
then -keeping the left nostril closed deep breath-in through right nostril
then - close your right nostril with thumb and breath-out through left nostril.
This is one cycle of anulom vilom.
Repeat this cycle for 15 to 30 minutes twice a day.
Children under 15 years – do 5 to 10 minutes twice a day.
You can do this before breakfast/lunch/dinner or before bedtime or in bed. Remember to take deep long breaths into the lungs.You can do this while sitting on floor or chair or lying in bed.
While doing anulom vilom, keep your eyes closed, concentrate on the third eye (point in between the eyebrows).
you have more options in Australia than in the US. All short acting brochodilators have potential side effects like insomnia. the "most gentle" bronchodilator is probably Xopenex generic name levalbuterol
I am not familiar with that particular med, but broncho dilaters are all stimulents and will speed up the heart some. That one may have less of that side effect than Ventolin though. Another option would be Xopenex. It doesn't have the stimulent side effects albuterol has.
I hope you find some thing. Some times the regular breathing treatments are needed, but you also need sleep.