Thank you for the query.
It is hard to tell what is exactly causing your symptoms as fat in your case obscures everything. Uneven abdomen can be caused by abdominal hernia
for example so the abdominal cavity ingredients are getting out on the one side.
Leg problems can be caused by nerves compression. Joint pains
are most likely caused by your weight.
I suggest you to visit a doctor (can be your regular doctor), have physical examination first. To see whats in the abdominal cavity, abdominal ultrasound
or better abdominal CT should be done.
Hope this will help.