Hello
Coughing from years with sputum . 
Now sputum with blood many times . 
These symptoms are suggestive of these possibilities , these include:
1 
Tuberculosis , as this may be the most common cause . Get in X ray chest P A view , blood for C  B  C . E S R ( if very high i.e. elevated >100 mm is suggestive of tuberculosis as well some chronic disease .  Also get in sputum for A F B .
2 
Bronchiectasis , this is another most common cause , however severity of disease associated with amount of mucus or sputum with blood . 
Get in  X RAY chest as well physical examination by a physician.
3 Asthmatic allergic 
bronchitis is another cause of such symptoms . Physical examination as well as clinical examination is important to rule out this disease.
Cancer , blood disorder , 
sore throat ( super added infection in allergic bronchitis) are another reasons beside 
mitral stenosis .
In my opinion consult  a chest & tubercular specialist and get his opinion .
As as concerned about treatment , it will be decided after proper examination.
Good luck.