Asthma Tips? Especially if it's from runners!!

Br
I went to a 5k this morning for Motts Children's Hospital with my student org, and I seriously only ran for like 6 minutes. Unfortunately it was really hilly for that first 15 minutes. I walked the remainder of the time (and came in dead last, but hey, I finished...), and when I first stopped running to walk, I could tell my stupid seasonal asthma was back. I was super short of breath like a fish out of water, my vision was beating with my heart and I had some white spots on the edges, and I could (tmi) taste blood in the back of my throat. This is normal when I've been running for awhile, but never for that short of a time period before. I know when to stop because of this limitation along with a heart murmur, so I usually walk it out after that so I don't, ya know, keel over. 💀
I started coughing while I was still finishing the walk and my nose was runny, but I have bad allergies too so I didn't think much of it. When I got in my car to leave I started coughing nonstop for a half hour and I've been coughing every hour for about two minutes straight and my exhales sound really raspy. I don't have an inhaler and haven't had one since middle school...and since it's the weekend the only options for doctors are urgent care and a hospital. I don't think this is that urgent and it will either go away on its own or I can put up with it until I see my doctor if I need to.
Does anyone with asthma have any suggestions about how to help at home for now? The coughing has given me one of those obnoxious migraines where when you cough your whole head hurts and nothing has helped yet. I'll take any advice.