Same here i lasted 4 days on Letrozole had an esophageal spasm so horrendous it lasted 3 days now I am back on Arimidex and just stopped that yesterday because of the right arm and hand tingling and severe numbness and my hand feels like the joints and nerves are on fire so I am not sleeping this is not a good quality of life as well as the massive weight gain from both !
So sorry to hear of your horrible and scary experience- I hope things go better for you. Take care. 