Good Morning Im afraid I dont know much about the human endocrine system other than what I have learned here or my endocronologist taught me. BUT! I do know that this part you mentioned?
it almost feels like my breath & heart skips every few minutes
Though, there are some "things" that can, indeed make that happen... It is important to get to your primary care physican or urgent care center for that. Get someone to just check / test / document the hear stuff. Really important to keep an eye on that while you other medical conditions are being treated