Shoulder stiffness and weakness. Doctor?

Hello Doctor, I have got a sudden pain on my left shoulder last night due to looking the computer for too long for studies. Post that I fell asleep. I wasn't very hungry so I had a banana for dinner.(I had a sandwich at 5 and prior to that i had my breakfast and lunch too)I woke up in middle of the night to pee and just after that I felt my body going cold and loose and I fell unconscious.(never happened before)I lied on the ground for 2-3 mins and then woke up and tried to fall asleep on my bed but my body felt too weak. In the morning the shoulder pain prevailed and I still feel very weak. I made sure I have my breakfast. What could be the cause of nausea and unconsciousness? Is it low BP? Do I need to consult a doctor? Kindly help clarify the issue. Thanks, Dipanwita