Was it a good idea to tell my ex how bad he made me feel?

In a nutshell, I'm 16 and I went out with this guy for quite a while, he broke my heart, I rarely talked to him since last July but the conversations never ended well. He triggered my depression, which I've had for several months, and it took so much out of me. I couldn't stop thinking about him and I tried so hard to be happy again. He knew I hated him, and he's been emailing me over the duration of the several months trying to start a friendly conversation but I never responded because I knew he'd either make me angry by saying something or he just didn't deserve to talk to me (he was really awful.) He emailed today, asking me not to ignore it, and he was seemingly polite. He said he tried to bump into me the other day at school, but I walked away. I don't know what he wants from me, but all I know is that I gave him everything, he tore himself away from me, and I've been trying to better myself ever since without being too rude to him because I still want him to miss me after all the heartache he put me through. I told him he didn't understand how I've been feeling and told him in a thought-out sort of way how hurt I was for quite a while. Bad move?