Intense Muscle Crvials and Lower Back Pumps

I am currently taking 150 mg Test Prop and 50 mg Tren EOD. My muscles have been locking up quite a bit lately and my lower back pain has been intense on back and leg days. It seems as if I am retaining a lot of water which might be a cause. I have LR's Nolvadex and Arimidex on hand but haven't used any yet. Might this take some of the water bloat down and help with the pain? What about the muscles locking up? What doses? Thanks for the help.