There is nothing wrong with attachment when it is mutual, and I agree with your statement
the problem is when in like my case, the other person does not feel the same way...that is what sucks big time. Now you are attached to a person that does not want or have the connection to be attached.

The fatal statement that collapsed my world with this girl was when we were talking about our situation and how I wanted to see her more often and she replied with the dreaded "I do not want to get emotionally attached" speech.