you are asking a question that could not be answered over the internet. we do not know anything about you your medical history. but more importantly we have no way of examining you and/or ordering any diagnostic tests. before attributing any medical condition to stress or anxiety a medical provider must first rule out all organic causes that could be attributed to your array of symptoms. i would strongly suggest that you see your medical provider -- someone who knows you and your medical history -- for a thorough diagnostic evaluation.
i sometimes feel breathless when sleeping on my side but i don't know if it's a health problem or just stress. over the past few weeks i've felt out-of-breath when falling asleep while lying on my right side. i wake up almost in a panic with my heart racing but i feel better when i sit up for a while and eventually can sleep like normal. this doesn't happen every night though and doesn't happen if i nap during the day. it also only started after i had a health scare (unrelated) while lying in bed which left me afraid to fall asleep. is this a real issue or just anxiety about what happened before?