I have struggled with OCD for 12 years and have been on medication, but it is worsening. I am concerned about possibly transferring tiny traces of waste into my kitchen, the food I prepare, and even into my mouth. What steps can I take to address this?
Such repeated doubts are from your worse enemy Shaitan and must tackle it to get rid of it. You should ignore these thoughts and doubts till you don't get it. If you care for it, it will continue coming to you and might also increase and make your life more difficult, but when you ignore it and keep on ignoring it whenever it comes, it will not come to your mind frequently.
Wassalam.