I still have days like this. And even after going to the ER back in August having many tests done on the spot and now seeing a lung specialist , I still panic on bad days thinking the worst is going to happen. I have to remind myself I've felt like this before and it will go away, (or at least go back to my usual sob because it never actually goes away for me, just some days are worse than others)
Try not to panic , as it makes it worse (it does for me anyways ) but definitely try to see your doctor or go to the ER as soon as you can if you haven't already! Having whatever tests you need done to rule out anything serious will help you relax on those bad days!

I started working out again two days ago after a 4 week hiatus from working out because my breathing got worse and I was just plain scared to work out again. Now I'm pushing through my sob even while working out, I just have to take more breaks to get a good deep breath. But I'm really frustrated letting my sob rule everything I do, so I'm trying to just push through, and hope for the best at this point.