Keep doing this for yourself lastchance. As regards your ex I'm in a similar position to you. My girlfriend of six yrs and I broke up recently too and I miss her everyday. Someone gave me good advice as regards relationships "hope for the best and prepare for the worst". Even if you and your ex don't get back together don't let that derail you. Keep thinking of the worst case scenario and learn to deal with it if it arrives. Honestly it's good advice I've yet to see if I myself can actually heed it though :-), but everyday I go over worst case scenarios. Look hopefully I'll never have to actually live through them but fail to prepare, prepare to fail.
Keep up the good work your not alone here