Re: Concerned, 20 year old man.
Arthritis? Psoriasis and psoriatic arthritis? Vitamin D deficiency might also give you muscle and joint pain. Gall stones? Gall bladder is near the liver.
Stop drinking, smoking, eating junk and having unprotected sex and you won't have to worry about all this.
Go to the doctor and get tested for diabetes. I wish you well my friend.