What you are feeling, light pain and breathing problem suggests that your asthma is not as well-controlled as it could be. Another explanation could be that you are experiencing side effects from the Rotacap®. It is possible that the dose is too high for you and if you are going to take this medicine you should divide the dose. But there is something else the Ventolin® Rotacap® is a short-acting bronchodilator. These days it is more common to use a long-acting bronchodilator combined with an inhaled steroid. Such a combination could provide better relief of your shortness of breath without the risk of side effects.
Good luck.