I too suffer when there is high humidity though suprisingly today here in NYC the heat and humidity are way of up there and I haven't needed to use my albuterol. My chest tightness up also and I can anxious like you when such an epsiode occurs.
First mention this to your dr. Humidity can be a trigger for asthma. Always carry around an albuterol pump. A spacer with the pump is even better. A spacer is a tube that gets connected to the mouthpiece of the pump. You would press the pump like you normally would but the mist goes into the spacer tube and you in hale it from the tube's nozzle. A spacer helps get more of the medicine into the lungs as opposed to the pump alone. I also carry a small portable batter-operated neubilzer. It's made by Omron Healthcare and you can get a new one cheaper on ****** then on the Omron website. Try to avoid going out when the heat and humidity are high. Bring cold water like Poland Spring and perhaps an Italian ice.
Hope that helps.