Hello I share your concern. Bleeding in stool is always a matter of concern it needs to be evaluated in detail to find out underlying cause for it. Since you have a history of constipation than it might be related to Fissure, hemorroids or any coagulation disorder which might have aggravated during passage of hard stool. Breathing difficulty and wheezing could be related to low hemoglobin level owing to loss of blood in stool. At the same time other causes of breathing difficulty and wheezing to be ruled out like asthma or lung and heart disease. In my opinion you should go to Emergency care immediately for physical examination, recording of Blood Pressure, blood investigation like hemoglobin, CBC, X ray chest. you may require blood transfusion or iron and folic acid supplements to regain lost blood and to restore hemoglobin level. Meanwhile try to avoid constipation and have lots of fresh fruits and vegetables with dietary fiber supplement. Hope this answers your question please feel free to ask for further clarification I will gladly answer you. Best wishes