Well, you are experiencing GRIEF over the loss of your relationship and the dreams you once held! It's natural to have these periods of sadness and depression. Do a little research into the "5 Stages of Grief" and I believe you will find yourself in the middle of this process. Note as you read about it, that the KEY to moving on to the next stage is to allow yourself to FEEL whatever comes up, rather than stuff it. So, even though the crying is disturbing, it's actually very healthy that you are doing so.
Here's one article that I found:
Relationships Ending: The Five Stages of Grief After a Break Up
(((((Hugs))))) Remember, you gotta go through it to get to IT. Everything will be OK. It really will.