This is an akward compartamentalized plan. Can you move the east bedroom to the west wall opening up the living area? Add a kitchen penicila with bar and crockery.

Let your wooden beam be as it is. put your Led lights in the other direction ( two on each side in one rectangle , so the total will be 16 units of say 10 watt each Led.), as to balance the horizontal and vertical shape. Don't put anything on the wooden beam to retain its the beauty.

area 12×16 feet

Kindly shear some pics