Keep your chin up! I can only imagine the hurt that you are feeling, but keep in mind that the self pity will only bring you further down. Focus on yourself and what will make YOU happy. Get training for that 5K and try to set an attainable time goal. Hit those tennis lessons and burn off that anxiety and clear those thoughts. I know it doesn't feel like it, but there is a lot out there to keep you going. I have to remind myself of this constantly every day.
I am new to all of this myself, but it looks like you are doing the right things to get through this. You WILL come out of this stronger no matter what the outcome is with the M. Remember that!
M 30 WAW 29 T 15 M 5 ILYBNILWY 3/8/09 Separated 3/14/09