Proper stretch

My problem is about the state that the penis must be to a proper stretch to work. I always apply heat before my routine, but when I do it my penis expands due to blood flow, this makes my penis more resistant to a average stretch force. From what I look when stretching it only seems to deform the base(maybe the ligaments). I’m not being able to proper stretch my tunica. Another thing is that I only have gained soft gains(length and girth), but my penis shape have changed, it was thicker at the middle, but now the girth is uniform. What do you guys think about?

Starting Size 26/04/2011 -- Length 13 cm Girth 14.5 cm --

--Short-term goal Length 17 cm Girth 15 cm--

--Long-term goal Length 19 cm Girth 16 cm--