Preaching twice

I have heard people talk about the difficulty of preaching twice on a Sunday. I have never thought this was a problem - eventful, yes; problematic, no. But I am beginning to change my mind. It's not the preaching or taking three services on a Sunday (I did this recently) but how do I relate what I preach to people I don't yet know? Whenever I preach it's always from deep within me. It comes from deep down and can take two weeks to develop from an idea into a beautifully formed work of art. I no longer have this privilege. On one particular Sunday I took two communion services at different churches. On both occasions as soon as I arrived, I realised that what I had prepared was inappropriate for the congregation. Do I carry on regardless or do I change it 'on the hoof ' ? What do you think? Well, I changed both services as I went along. Did anyone see the join? I don't think so, but it totally drained me as I tried to adapt what I had prepared for the people in front of me. 'Didn't God give you the services?' I hear you cry. Well, it's not what one gives, it's how one presents it - same message, but different delivery. I can see Sundays are going to be 'eventful' for some time.