Yeah better to check it out and u will be ease too,if ur worried about ur heart,have u done any ECG yet ? if it came out fine then dun worry,the heart is likely to be fine.And yeah Anxiety & stress does cause some weird symptoms too.
While you got some good suggestions, I think it's really important that you get a medical check up if these symptoms have come on suddenly.
That "butterfly" feeling is very common with anxiety and actually, so are the heart issues, but I still think it's best to rule out anything organically wrong before you go off experimenting with ANY substance.
It's always better to be safe than sorry.
I'm sure there is nothing wrong with your heart, but only a doctor can tell you that for sure,
What you are describing are common anxiety symptoms and i don't think they are related to a medical condition.
I do experience the brief BPM increase while taking a deep breath and it is normal and is related to the pressure happening while the lungs are contracting. But after the brief increase it is followed by a slower heartbeat rate. Deep breathing exercises are always good to reduce you heartbeat rate and lower your blood pressure.
As for the tingling itchy feeling they are very common anxiety symptoms.
You could always consult a specialist to see if you have any allergies about those itches but i really think they are related to stress and anxiety and you seems to know it's stress/anxiety that is causing them.
If you need anymore information on natural ways and or traditional ways to treat your anxiety you can send me a PM and i will be pleased to respond to you and giving you all advices i have in my bag of tricks.