I understand I am not a woman but I am a guy who has watched these (types) of guys in action. First of all its not about timidity or being weak really, but you want and need friends and to these guys your need/want makes you easy prey. To them they think you are willing to put up with anything in order to keep your friends. These guys aren't really your friends, unfortunately, it is very hard for men to separate sexual from platonic especially with an attractive woman. A lot of women can't be friends with other women they just don't get along. I am not sure how you feel about this suggestion but I am sure you could find a great group of male friends that are gay or just one good gay guy friend and they will be truly interested in you rather than just having sexual with you and taking advantage unless it is for something other than sex. You need someone who has your back no matter what.