In my experience (note: i am a man, and I see this question as gender-neutral), these kind of wishy-washy statements that 1. Express self doubts, while 2. Not taking steps to correcting the cause of those doubts, and 3. Avoiding commitment while also 4. Refusing to break things off, are really just trying drop enough hints to get their partner to break up with them so they don't have to be the Bad Guy™ by doing the breaking up themselves. Other classic variations are, "I don't know what I want," and "I love you but I'm not in love with you."