Hi, this sounds very familiar, I was diagnosed with allergies, pollen in summer, dust mites in winter, and I think the medication helps. I would like to get off the medication after about 4 years, but not sure if I can. I think anxiety must be a big cause, my doctor told me even she finds it hard to control her breathing if she finds herself noticing getting short of breath, she says you can't easily separate the physical causes of asthma from psychological ones. (She gave me an inhaler by the way) She made me feel better because I was getting the feeling that the rest of the surgery thought I was a hypochondriac, I had tests where they seemed to be dissing the need for a test at all, I ended up totally confused about whether I had asthma or not, so didn't use the inhaler. I think I'm a lot better now, I even managed to get over a shortness of breath/panic while on a shop till by breathing evenly and telling myself It would pass. I changed my job and don't get them at work now, but sometimes while sat in the evenings, I think they are related to hot flushes.
I am lucky, I can wear layers all the time, I even go outside sometimes to cool down. Sometimes I take advantage of a hot flush in the middle of the night to go to the loo, it always cools me down in our climate!
I think exercise helps, not pushing yourself when your chest feels really tight, but experiencing that "healthy out of breath" breathing which is so different and where your breaths actually seem to provide you with extra oxygen. I've lots a couple of kilos too, would like to lose more but at least I'm maintaining weight (cross fingers) Good Luck to you all.