Brother stole from me?

I am 17 and my brother is 14.I bought some candy yesterday,I was saving it to give to my friend for her birthday. I come in my room and all of my candy is gone except for 3 pieces. I ask my brother about it and he tells me that he ate it then he laughs about it. I go into his room and see my candy wrappers on the floor. I was incredibly angry and I went and told my mom and she didn't say anything she didn't even care. So I started cryinh(I cry when I'm really mad). My mom said she will buy me some more candy but I know she won't. I just find it shocking that my brother didn't get in trouble for STEALING from me. Am I overreacting?