I have felt this way too, but I have to point out that there is not a simple solution. You can't just "stop" cosleeping without using some sort of sleep-training approach, and they often involve CIO tactics. Whever anyone gives me that advice -- just "stop" -- I feel very frustrated and as if my situation is not understood. Sometimes we need support and understanding more than we need to be told "just stop."
And for some babies, cosleeping is not a "choice" that is made in the first place. For my son, cosleeping was something that he clearly *needed* and not something we did because we read Sears books.
We nightweaned after my son turned 2 -- it took about 7 rough nights, with lots of tantrums, but also lots of reassurance, snuggles, conversations, etc. After a week, cosleeping became a much better experience for all of us, and ds even began spending part of each night in his own bed. Sort of a "best of both worlds" scenerio. That one week was rough -- but manageable, and my son did not feel abandoned.
"The No-Cry Sleep Solution" is one helpful book.
Another is Jay Gordon's "Good Nights"