Hi Alisonmpg..................what a sad post and I really felt for you. When you feel you have found your soulmate it must be devastating to then find that he has "changed his mind" for whatever reason. Look into your heart and be honest with yourself. If you did everything you could to make the relationship work, even if it was long distance, then you can hold your head up and know that the fault does not lie with you but with him.
Hard as it is you just have to accept that, for whatever reason, he just does not want to continue. Once you have done that you then have to decide how YOU want your life to go on from here that will make YOU happy.
I wish you all the best and hope you find your way forward that is the best for YOU.