I meant to add, one trick I learned to control panic.
When your chest gets tight, and you get shortness of breath, you tend to be so conscious of breathing, you end up breathing too hard, like you can't get enough air.
You are actually taking in too much air and it never seems like enough... but that is because you are creating an imbalance putting too much oxygen in and less carbon dioxide.
This is when the panic begins to set in and your body starts to go into shock. It all just escalates if you don't stop it.
When I feel this shortness of breath and anxiety coming on, I do the opposite of taking in more air. I try to relax and breath normal, and it's not easy, but stick with it, and you will feel more relaxed and in control. You have to keep in mind, you are not going to die or stop breathing! Even if you passed out, your brain will control your breathing and do a better job, with you unconcious.
Sometimes controlling your breathing means stop thinking about it, and don't do that deep yawning and hyperventilating. Relax and your breathing will come under control.
At least for me, the breathing is key, and I hope this helps.