Anshulji,
You are beta thal with an alpha triplication. This can lead to an intermedia condition, because far too much alpha globin is being produced and not enough beta globin is being produced. This creates an imbalance and the excess alpha chains form tetramers that basically cause havoc in the body. It also means that the red cells produced can be unstable and easily destroyed, resulting in the large spleen.
Has your doctor suggested a splenectomy? In this case, it may be of great help (I usually do not support splenectomy, but the triplicated alpha gene does present unique problems).