So sorry to read your update OP. He has responded so disrespectfully! So he finally got your feeling after the sex analogy!! Honestly 
Although your analogy was super!!
But your latest update worries me. I don't like the sound of it at all. You shouldn't have to work so hard to leave a good memory with him!
It shows how much you admire him and you don't want him to think bad of you!! OP if he really cared to think anything of you that much he would have proposed by now!!!
You would know the ground reality best as we are only an online group but I agree with pp who said YOU need to turn around and tell him - "you know actually you are not the person who I thought you were and wanted to marry. Bye"
That will really leave a better impression of you on him than being the perfect girl! He will see a woman who stood up for herself, not a girl trying so hard for him.
And if he did really want to marry you, that's the point he should ask it. If he was just stringing you along, he will let you go.
So you get your answer and also he sees you with respect finally, as someone who stood up for themselves. That's the impression you want to leave with him.
Playing perfect now will only come across to him that not proposing was a good idea!!
Best wishes 