What Causes Weakness And Pain In Arms,legs And Dizziness?

I ve been having issues for over a year now, I very weak in my arms to were I can t cut up my own food open a bag of anything, my legs hurt all the time, cant sit one way very long because my back will kill my head, all I m very sleepy, it s like I never went to sleep, I stay very cold at all times even if the temperature is 90. Alot of foods I once love now taste real funny to me,I ve lost alot of weight. From time to time I get very dizzy and my heart feels like it beating way to fast and I can t breath, I have to have a fan on at all times to keep the air moving or I can t breathe. The last 2 weeks I ve been having alot of trouble seeing. Can you please give me some clue to what s going on with me.. Thank you for your time