What is the main conflict in Twisted by Laurie Halse Anderson?

Tyler is the narrator of Twisted. He considers himself an unpopular kid entering his senior year of high school who is constantly struggling with suicidal thoughts. He has always been a small guy who is teased mercilessly and hence he tries to stay under the radar. However, he decides to make a name for himself and uses graffiti to do so. However, he is caught for this behavior and put on probation. He has to do community service. This leads to him beefing up and taking on a whole new body look.