Hi
Welcome to the forum!
Inhalers give instant relief provided the technique is correct. This is true for regular users. If you have just started, it will take you time to settle down. It could be possible that the breathlessness is due to other causes like anemia, heart problems, gastric reflux etc. However it is too early to say. Please continue the inhaler, read the technique of taking it from the pamphlet insert and try to follow this correctly.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!