Hi! When I read your post I remember feeling exactly the same way when my daughters were 15 months. In fact, I went back to the website that I have kept up for my girls since they were babies to see what I wrote back then. Sure enough I was frustrated about many of the same things. It was right at that time that I began the initial phase of weaning out the 2 naps a day. By 18 months they were both down to 1 nap per day. I even wrote a comment about my eldest that said, "Rick and I want to know where our happy baby went!" I wrote this because it was right at this time (15 months) that her tantrums picked up, she started testing her boundries, she expressed her frustrations physically, and most of all she fought her naps terribly. She even learned the word NO- ugh! The good news for us was that both girls were down to 1 nap by 18 months and they both started to show more affection for us on their own terms which was refreshing among all the new discipline stuff we were dealing with. I did start some basic time-outs at 15 months. Unlike the experts feel, I used the crib as a time out place because she was still so little. Sometimes I had to do 3 very short ones in a row before she would follow a direction. As she got older I moved the time out to the bottom step of our stairs. They don't really understand time outs until much later, but I wanted to build a foundation of following directions early on.
Hang in there...I always feel the "middle of the age year" is tough. 18 months, 2 1/2, 3 1/2, 4 1/2 etc.... it seems the beginning and end of a year things run a little smoother.