Yes I can relate  Heretofloat.  The feeling when someone dumps you and then moves quickly onto another relationship (a marriage in fact!) can feel like a stab in the heart.  Plus wanting to get even thoughts are there as well, wishing him the suffering you are feeling is natural in a way.

It would be easier to move on if you don’t have any access to what is going in his life, e.g. social media, etc.

Good for you for making the attempt(s) for the gym Hertofloat.  On the days you are not plain up to it, just try doing a walk around the block.  Just move your body and get out into the world.

Hugs and love to you for your suffering.

Mark