Can stress cause prolonged shortness of breath, chest pains, diarrhea, nausea, and tachycardia?

Yes, it's possible: Anxiety and stress can result in many physical symptoms, including all those you list. However, it's also important to work with your primary care doctor to make sure no additional conditions may be part of the problem. There are good treatments for anxiety, including talk therapies as well as medications if needed. Of course you also want to review and simplify any sources of stress!