Welcome to HCM,
After going through your history most likely you have Rheumatic severe mitral stenosis
and you are rightly advised surgical intervention as soon as possible.
You have given mitral valve area which must have been measured by Echocardiography
,we need to too know other details like condition of valve and degree of calcification present and severity of your symptoms if valve is pliable and suitable for baloon( PTMC)intervention it is good intervention will help you significantly and your cardiologist would be in better position to tell you if this procedure is useful for it.
If valve is non pliable and lot of calcification is there then MVR may be better solution as prosthetic valve requires life long anti coagulation with PT(INR) monitoring for which good compliance and follow up is required.
If suitable and good result can improve your hemodynamics and symptoms up to 5 to 10 years.
You can ask specific details in this forum with uploading your investigations.