Life as a CFI

Well, I officially have about 4 hours of instructing under my belt (not another notch on the old belt-quote from what movie?). The first flight I had was with a friend of mine who also wants to fly professionally. The plane I received my CFI checkout was a Piper Warrior, of which I've never flown, and is similar to the Piper Seminole, in which I have about 150 hours. This was the plane the friend of mine wanted to fly for his first lesson. I felt comfortable with it on my checkout, but as a first lesson I felt uneasy. The lesson itself turned out to be very constructive and my student ended up enjoying the flight. I, however, felt uneasy for almost the entirety of the trip. Maybe it was the plane, maybe it was instructing for the first time, but it was one of those flights I did not enjoy. I was even skeptical to give my student the controls to fly the plane. He did very well and we landed safely, although there was quite a strong crosswind which didn't help my uneasiness. Afterwards I felt completely drained and fatigued. Fortunately, my next flight, which was with my brother in a Cessna, went exceptionally well and reassured my desire to instruct. Flights following this flight became more and more enjoyable and I'm actually becoming comfortable teaching and letting my students fly the plane. I'm very excited for what's ahead.