Go forth with your 180. It will work only if you stay with it. I'm am in no way saying be mean to her, but she expects you to be nice, attentive, and caring. Take care of your self for a change. Join a gym, work out, run, find hobbies... I'm sorry, but it is apparent that you have low self esteem by some of your writings. Remember, there is a reason that she was with you for 6 years! You are probably one hell of a guy. Pick yourself up and take care of YOU. Remember to be kind, but throw a little "as-if" in there. She sees the low self esteem. Be more assertive, self loving and confident and i would almost guarantee she will notice!
Good luck my friend.
Your esteem may have become stripped over time by being so attentive to her, but not recieving the proper reciprocation, because she had you too low on the totem pole. You don't realize it till it's too late.
I think you'll be fine, and this will be a situation for her where the grass is not greener on the other side. If she's been spoiled to attentiveness and faithfullness, and gets out there in the world where it's "all about me" for these other men, she's not going to be too happy how that feels.
Take care of yourself for a change and listen to what some of the other members are saying. I'm not sure you should have the attentiveness and faithfullness guage cranked all the way up, when she is not going to "pay you" for it. Actually it works in reverse. You get dinged the harder you try.
Perhaps you guys are in a strange "persuer-distancer" arrangement, where you need to pull away and do your own thing, don't worry about her. The distance and gap will create a need in her, she just may begin to pursue you.