Hi Loublou and welcome.
Iīve had similar symptoms and in my case it was related to pyrosis or heartburn, but the symptoms were just like you describe. In fact it was scary and I thought I was going to have a heart attack.
It was Gastroesophageal reflux disease and I had to take medication for that.
Itīs best to see what your doctor says as, but it sounds like stress, not withdrawal.
Best of luck.