New Inspiron 5558, Right Angle DC Power Plug adapter

I have been searching for a right angle adapter for the DC power plug.  The male plug diameter is 4.5 mm (0.178 inch diameter).  The existing male plug is straight and the cord receives much stress at that point because the female receptacle is located on the side of the laptop rather than the back.  A right angle adapter will relieve that stress.  There are many right angle adapters available but I have been unable to find any of the correct size needed, which is much smaller on this  laptop.  Looking for a source!