Not sure how long you are in the process of trying to step down, but here's my exp:
I was constantly being used, sometimes multiple parts in one night. I was also the school overseer and a bs (in every sense) conductor. I asked politely to resign, even temporarily, but was continually rebuffed, and "encouraged" to keep going. I went on for about another year, and then changed congregations with the real purpose of never serving again.
When the time came for re-appointment by the elders at the new hall, I meant to say "no", but when I opened my mouth "yes" came out. I guess because I was so used to saying yes to every assignment. The minute we left that back room I was kicking myself knowing I had defeated my whole purpose. I shortly thereafter -maybe 2 meetings later - resigned for good, stating personal reasons and needing a break. It was much easier at the new hall as there was much less of an emotional attachment to people I barely knew, and they for me. It was a little awkward (but only a little) and made my fade much much easier.