That is common. Eventually it will lessen as your body adapts to the med. It is not a steroid and there are no long term side effects.
Yes, there is a difference between Singulair and a steroid inhaler. Some people do well on the Singulair, others, like me, get no results with it. If you think it is helping and want to stay on it, this is another drug you ought to check on buying in Canada. Without insurance, I would suggest checking on everything you take. You might find some bargains.