I have symptoms of muscle cramping and pain all over my body. i had a random urine test done and my albumin levels were just over 300 mg/l and my creatinine levels are 600 mg/dl. is this macroalbuminuria and would it be causing my symptoms?

If the numbers, especially the units, you gave are accurate, you only have mild microalbuminuria (50 mg/g) and that has nothing to do with pain and muscle cramp. However, a systemic disease with those symptoms, e.g. statin induced rhabdomyolysis, can cause mild microalbuminuria. You need more tests than just this urine result for the definite diagnosis.