Welcome to QuitTrain, @BmoreRaven and congratulations on quitting smoking. I really can't tell you anything about nicotine pouches as people here have quit in a variety of ways but hopefully someone else can add more insight on them.
As Doreen stated above, if you are having serious anxiety issues, it is always a good idea to check with your doctor.
Congratulations on 132 days smoke free. I smoked for roughly 20 years and quit at age 39. Everyone's quit is different but it did take a while for my breathing to get back to normal. I did start noticing my breathing was a lot better after a few weeks but, at times, I was hit by heavy and nasty coughing reminiscent of what I experienced when I smoked. I was told that this may be due to my lungs cleaning themselves out after years of abuse.
Everyone's quit is different but the key to successfully quitting is just to not smoke. You definitely want to try to get off nicotine at some point as well (since you are using pouches as a nicotine replacement treatment) and I'm glad you are doing this. Sounds like you are going in the right direction.