To be honest here I consider whey a food item and not a supplement. It can be cheaper than meat, and more convenient at times than cooking meat. You use whey to help you hit your daily protein requirements.
You could try a different form of creatine and see if it gives you the same problems.
Also not what you asked about here, but there is a plethora of anecdotal evidence for NAC helping significantly with OCD symptoms. If you are taking meds for it already talk to your doc before you try this though