Hello,

You can get a much better starting result by drawing a tangent line off of the leading edge of the wing and moving the fuselage forward. You'll still probably need to carve up the blend into a few sections over the course of the connection, but the wing position seems to be causing the blend to fold over onto itself a bit. I've also found it helpful to keep a few copies of the original surfaces complete to use as construction surfaces especially when blending. If you have a more simple version of the model without holes it would be helpful to post that.