Thanks for the query to H.C.M. Forum.
Since , how many days , you are having this pain.
Here one thing is clear that pain may be due to ,
Enlargement of spleen
( as bulging is there ),
Disease in stomach ,
may be due to involvement of lower lobe of left lung ( pleural rub, thickened pleura, pleurisy
Since the nerve supply of diaphragm ( membrane separating thorax and abdomen) and shoulder joint is same phrenic nerve
, so any pain beneath or around diaphragm may irritate phrenic nerve , hence pain also in shoulder joint.
In my opinion get in an ultrasound
of this part and also X ray
of lung .
Either upload the report over this site or consult a physician and get his opinion.
Hope I have answered your question.
If further any question I will help.