i just dont understand what could be wrong with me but getting so fed up !!

I constantly have to exhale really deep but while i exhale my shoulders,  shoulder to shoulder horizontally right above my sternum( the dip between pecs), feels like a pulling pain. somtimes this causes me to feel dizzy, a very dry blocked nose (i literraly have to pull the nostrils apart to feel the air), and the get either palpitations or really fast heart beats.

If i go a few days without doing the exhaling excersize it really hits the fan. My shoulders feel so achy, my heart beats really fast just getting up, the back of my spine literraly in the middle hurts.

The first thing i thought of is anxiety but im not anxious if anything its this thats causes me upset. If i dont think about it until a feel some sort of pain from it.

When i do the excersize and breathe out slowly i hear all sorts of crackling from my lungs and its only when doind the excersize for half hour or more the crackling slowly subsides, and then everything relaxes. The shoulders relax, heart goes slower and i start to feel slightly better only for the same thing to happen a few days later.

everytime i go for number 2 (once to twice a day) ive always had loose movements. its been like this since it started say a few years ago.

Ive been to the doctors and they have ran all sorts of tests but dont find much.

Ive had ekg, holter monitor, blood tests, spirometry tests, stool test and etc

can anyone identify what i might have ? any reply would be most welcome.