Help save my rhomboid? Strange behavior

[RDMike]

It started this weekend when I was out of town and my roommate was taking care of my tank for me. He was out and normal on fri and my roommate did not see him sat or sunday. I came back monday night to find him hiding and not eating. His skin was also discolored and not normal looking. I dose my tank with prazipro just incase it was fluke that day. I did not see him all day tues and assumed he passed away. I saw him today still hiding, not eating, blotches, and occassionally hovering around the sandbed to different caves. I am not sure what I should do at this moment to help save his life. Thanks everyone