I'm 11 months out from the dissolution of a 7.5 year marriage. What a hard thing. Be glad that your relationship was there, and be glad you found out you were not right for each other right away. It took my ex and I years to grow apart. 'They' say about 1 month a year to get over a person, so for me that was 10 months or so (we dated a while before getting married). I still am not ready for a full-blown relationship, but I have started looking for some casual dates (not casual sex) just to reacquaint me with women and get back into the whole scene.
I've focused the whole last year on basically discovering myself again, and doing things that make ME happy, something that got lost in the mutualness of our relationship. So I crossed some stuff off the 100 to do before you die list, spent time with friends again, took up a few new hobbies (try building your own speakers).
Everybody deals differently, and its okay to be sad and angry and depressed for a while. Just try to remember that you had a life before, and that you will have a life again. Also remember that you are now a larger and more complex person due to the experiences you were able to share with her (and she is too). Relationships just happen, and there is no 'right' or 'wrong' time for them to start, end or continue.
If you want to take the edge off your depression, take St. Johns Wort. It will kind of fuzz the sharp pain (it is widely prescribed in Europe and really does work). It also builds a tolerance after a few months, and by then you won't need it. Don't EVER drink alone, not even a beer, for a few months, there are no answers there.
Read this book "The Four Agreements" by Don Miguel Ruiz. It will help you find a new perspective on humans and their relationships with others. I have read probably 2000 pages this year, from Marriage and Relationship book to Tantra, and these 120 were the finest.
Don't ever forget that what is here today is gone tomorrow (and that includes you) - so make the most of each day with yourself, and if it happens for you, another too.