Has someone else take credit for your work?

I found out recently that I was moved to a different section because of “perception” that my co-worker (who, mind you, is lazy and takes about 5 breaks a day) was seen as a “harder worker” than I, when in reality this is completely untrue. I developed a consistent system for the programs we handle, try to improve them and keep track of them, in addition have additional jobs and responsibilities outside of work to keep me busy.

I was fuming when I heard the news that our boss thinks that she works harder than me. I don’t work in that section anymore, and I am so glad I do not work with that co worker anymore—so I am trying to look at this as a blessing in disguise.

Has anyone else been in this situation? What would you have done? Should I just let it go, move on and do the best in my current job? It just irritates me that I did not get recognized for how I held up that section.