Depressed

I have had seven relationships in past and each guy left me for some reason or the other. The last guy I was with I had entirely imagined my entire life with him. There has always been one thing in common, each one of them said "u r a great gal to be with and ur husband will be the luckiest". If I m that good why did anyone left me in the first place. I have become very touchy on this topic and am not willing to fall in love again or even get married. This thing has completely ruined my confidence. What is that I should change in me? How should I cope with this? I know this might seem stupid to many but I really need help.