The lower number - 50 - is more concerning than the upper number. That's pretty low. Who took that BP? A doctor or nurse or other qualified medical professional?
How are you feeling now?
https://www.healthline.com/health/low-diastolic-blood-pressure - that's some info about a low diastolic pressure - the diastolic pressure is the number on the bottom. Definitely give your doctor a call. They may be able to do a phone call with you about this at first, or decide to have you come in.
Thats a wide pulse pressure. Your systolic is essentially giving you info on you co (cardiac output) and diastolic on your tpr ( total peripheral resistance).
Yes , you should. The arm pain and 140 B/P is high.