I have experienced the same feeling recently. It felt like I wasn't getting enough air in, and I kept on yawning with barely any relief and it went on for hours and I ended up working myself into a panic attack and I decided to seek help from a nurse over the phone and she told me that I needed to try "abdominal breathing" by inhaling for about 4 to 8 seconds through my nose while pushing out my stomach and hold it for 4 to 8 seconds then slowing exhale through my mouth while tightening my stomach, which was around 8 seconds. You can start off by doing these breathing exercises 4 cycles in a row and work yourself up to 8 cycles in a row once you get used to it. I notice that when I am under a lot of stress, I tend to forget how to breathe properly and hold in my breath lot, so that is what triggers me into feeling out of breath. My doctor told me to do these breathing exercises every day even if I am not under stress so that when I do find myself in a panicky mode, I will already know how to control my breathing.

I have this. I found out I have a form of Dysautonomia called pots. Basically your brain doesn't always send the right signals to your body. It could be "pee now or your going to pee yourself" and it's just a trickle, it could be hard time breathing it could be "heart I don't feel like working right now so whatever you want" and your heart stops or is irregular (my heart stops and I pass out). Many other problems as well. It could be this.

i was like this as a child, and sounds like the asthma attacks i use to get. have you ever talked about asthma with your doctor?

They literally strap you to a table and sit you up. It's called the head-up table tilt test (HUTT). If you don't throw up or pass out (15min), they put a pill under your tongue to increase heart rate and simulate exercise. If you don't pass out or throw up (15 min), you most likely, don't have pots but may have another type of Dysautonomia or none at all. It's 30 minutes in total.

I have experienced this with both anxiety and panic attacks. It’s worse when I’m having a full blown panic attack. I don’t know if I ever had it for weeks straight but I have had it daily just not the whole day. Some days have been worse that others

I actually ended up getting an inhaler for it but it can raise anxiety a little because it’s a stimulant. It does help me breath better though