During my dance class I had a head rush and saw black spots, is this a symptom of asthma?

I'm not sure if this is asthma or not, but I wanted to ask if these symptoms are asthma symptoms. I am a dance student, 18 years old, and I have been studying at a very high conservatory level for the past year. But for the past few classes I've taken, I've gotten to a point in the class where I can't get my heart rate down. I stop and try to control my breathing, but have a tightness in my chest (which feels like when my heart rate is really up, but it just won't go down). I am able to breathe normally, but then I start to feel dizzy (lightheaded) and see black spots. For a second I can't see anything, like a head rush after lying down for a while. But this is in the middle of class and I've just been jumping around! Usually they pass, but it takes me at least 10 to 15 min after class to get my heartrate back to normal. I don't know if this is asthma (i've never had asthma in the past). I'm in very good physical shape, and don't understand what's happening. I have been told by teachers that I tend to hold my breath when I'm working hard, but I've been working on really thinking about breathing regularly. I mean, that would sound like a cause, but this feels way different from what i've experienced in the past. I've never gotten to the point where it scared me. At first I thought it was dehyration, but...i'm not sure anymore. If anyone has any idea of what this could be (or if i just need to work on my cardio) I would really appreciate it. Thanks!