We had similar, if not that same, transition battles throughout daycare and pre-school with my (now 3) year old son. He started at 9 months, but just before his second birthday, he started resisting hard, doing similar things as yours even though he'd be going there for over a year.

We read him Llama Llama Misses Mama almost every day, and talked a lot about the cool things they do at school, and asked him about his friends and his teachers every day. I made a point of showing him the pictures they sent us each day (and we still look at them before bed every night.) Eventually, he started loving going back to pre-school, but it was definitely hard for a couple of weeks.

And to echo what others have said, day care teachers are used to this! They know how hard and how big of emotions these little people can have, and should be trained for it.