You say so many bad things about yourself and I am sure a guy like that knows when he meets someone who is insecure and knows how to take advantage of this situation. So it is HIS fault and HIS problem and not yours.
Try to work on your self-confidence. Everyone here knows that you are pretty and that you have many skills- and that is what it's all about. Mr. Right will not be the prince on the white horse but there will be a good guy for you.
(My granny told me when I was thirteen that I would never get a man with the character I had and I believed it- but it turned out not to be soo complicated )