Sorry to hear you are feeling lonely. You are not alone in your feelings as many above have expressed and at times I feel lonely also. However, when I logically think about it... being single is one of the best gifts I could ask for now in my recovery.
I am actually grateful that I have the opportunity to be my age with a good job and thankfully a lot going for me and not be "tied" down in a relationship and have a lot of freedoms because of it. There is good and bad to everything. So, for now I am focusing on the good things that come with being single and there are many if you really think about it.