I've always had an annoying cough. I was diagnosed w/ asthma 2 years ago but I breathe hard and sometimes twist my body to get air, how can I control it?

Talk with your doc. As soon as you can. Asthma can start as an annoying cough but can get worse so that it's hard for you to breathe. Different inhalers and pills can help heal your airways and prevent asthma. Also, you & your doc can figure out other causes of shortness of breath. Think about your surroundings [dust, animals, smoke, fumes, mildew/mold]. Any new triggers during the last 2 years? Hope this helps.
Possibilities... Sometimes, there is more than one reason for a cough to be present and it will not resolve until all the etiologies are treated. For asthma, you would minimally need bronchodilator and steroid inhalers. Other possible etiologies include gerd, sinus disease. These have different treatments so you really should be re-evaluated by your doctor so this work-up can continue and treatment rendered.
R u using your meds? Most common reason for uncontrolled asthma? Not taking medication everyday. Inhaled cortiocsteroids used routinely control ~80% of persistent asthma. Smoking? Stop now. Immunotherapy can cure asthma when allergens are properly identified & you stay on the program. Anti-ige therapy employing monoclonal antibody is also very effective. Take control. If you're doing all this go get a second opinion.