adobe illustrator - How do you combine two paths into one, or is there a better way to draw this shape?

So to draw this crystal I used the pen tool for the outline and used line segments for the inside lines. Then I joined all the line segment anchors. I was left with two paths: the outline, and the inside lines.

I would prefer to draw this so the entire shape is made from one path. Is there a better way I can draw it to achieve this, or is there a way to combine the two paths into one? I can't seem to do it with the pen tool without it wanting to delete anchors when I just want to connect the lines.