Stiffness in legs arms hips

I am a young diabetic 23 years old been diabetic for 6 years now and I am suffering bad my recent a1c was 5.6 I have severe aches in knees hips and lower back I also have body cramps with jaw cramps and shortness of breathe I have been having extensive tests done to find the cause to my problems and nothing has been found so far I am wondering does neuropathy cause stiffness and I mean extreme stiffness in lower back hips and knees I am also having difficulties walking as my legs will just give out and burn and ache terribly my last emg test 6 months ago was negative and so was my brain MRI for ms and Parkinson's I am worried as im so young but suffer with all these problems I also have a constant sand like feeling in my eyes which is painful and never goes away please someone help me