Of course hugs are not always sexual. It's a shame we are living in a time where everyone has to get so paranoid about supportive gestures being misinterpreted as exploitative contact with a minor by an adult. But a lot of bad behavior by adults got us to this point.

Your teacher who wanted to be supportive of you with hugs sounds like a nice person, but I think she did go a little too far in telling you that you could always come to her for a hug. That could be read as her encouraging you to be overly dependent on her emotionally.

I am sorry you are going through the difficulty of having panic attacks. It's normal to want support. However, you are at a point in your life where you need to be developing "self-soothing" strategies. Middle or high school is not really an appropriate place to be expecting members of the staff to be involved in physically comforting you on a recurrent basis. Some psych professionals would say that runs the risk of infantilizing you.