Has anyone managed to successfully get an ex back after months that?
Yes. By showing on social media how happy I look. Announcing gym progress. Any progress. By keeping funny posts with lots of likes public. Now, after some growing up, I highly recommend you do the opposite. Dont do any of that. You seem to suffer from cognitive dissonance and trauma bonding like I had. As much as you love them let them go for good. They didnt love you for you; they loved you because you were an object that gave them happy feelings and they mimicked it back at you. Thats not love, definitely not healthy. IF you two would be back together it would be very short lived; that is not a relationship nor healthy. I purposely typed this part last. Move on and eventually you will get over it. Seek psychotherapy. Love yourself.