With those you have been with, have you told them about your anxiety problem?
To really get close to someone, I think you must totally expose yourself to them; to trust them. This mean exposing yourself to huge pain should they reject you when you have given them all of you, they could reject you completely. But, there are no half ways with love. I think its important to get as close as possible to someone for as long as possible before marrying.
Me? I was in love twice. Both times was dumped. The latter got together with my housemate, who was also my friend. It hurt like hell. I couldn't understand why it happened, Id given her all of me. I though I knew her not to be cruel.
Havent taken any chances with my heart now. I aim low. Pursue women I don't really want. Play games with their hearts. I'm tired of others loving me and not reciprocating. Im tired of guilt. Its either lonliness, guilt or pain. Can only be the first or last now. But the last has the option of more, much more. Life is only truly lived in love I think.
Hope this is of use.