Troubles Breathing need some help

Hello everyone, I'm hoping to get some help or any suggestion be them your own or even a link to an article that might help me.
Skip to the last paragraph for my question and brief description, the mid section is my story which lead to my current problem.

From the beginning. (Should mention I'm only 22 male) I broke my wrist a year ago so bad I had my whole arm in a sling for 1 month and I had my cast on for 3 months and had to do physio for like 2 more months, good news is my wrist is nice and healthy minus the limitations I have at the gym plus flexibility. The bad news I had picked up terrible eating habits and for 3 months I couldn't go to the gym and for another 2 months I was afraid to go back because my wrist was in so much pain.

So with these bad habits and no longer maintaining a healthy fit lifestyle anymore I went from being a healthy 175Ilb ( September of 2012) and about 3 months ago I hit my heaviest which was 225Ilbs I have the stretch marks to prove it.

Presently. I got really motivated to get back into shape once I took the time to really look in the mirror and see what I was doing to my body, I think I'm beautiful and I like to think I have a good self image even though what I see is different then everyone else. I started going to the gym off and on so maybe 2 times a week in September, I got serious in November, I now try to go at least 4 times during the week after classes usually with a break in the middle and on the weekend I do 1-2 hours of just cardio. I also got my eating in check.

The good news is recently in the past 3 months even with indulging on Christmas and my Birthday I managed to lose 25Ilbs and 7" off my waist.

My problem now.Now I've had asthma my whole life it was really bad when I was younger. Once I got healthy and in shape my asthma almost seemed to disappear I used an inhaler last summer (when I was my heaviest) for the first time in 8 years. I've had to walk out of some college classes because of it.

My biggest problem right now is that my body is changing and my lungs can't keep up with me. I feel like I can do so much more if I could just get my breathing under control.

Today, I was working out with my trainer (I got some sessions for my birthday) and my inhaler ran out last week, and I'm out of refills and because it was my birthday a few days ago my Health Card expired (OHIP / Canada health care) so I can't see a doctor without paying up front, so at the end of my workout I had an asthma attack first time in 10 years, I convinced her not to take me to the hospital or call an ambulance because I can't afford it, she instead had to call my pharmacy and they gave me an inhaler without a prescription I just showed them my old one. Its kind of embarrassing to have an asthma attack in front of a full gym and to have your trainer rush you to their car to drive you to the pharmacy.

I'm back on my inhaler (asthma) so that should help. But is there any breathing techniques that I could use to increase my performance and hopefully not have another episode. Any suggestions would be a big help or even a link to an article or another post would be great!