Daily Dilemma: Hitting.

My sweet little boy Braxton has been hitting. A LOT. He was so sweet when he was a newborn and for a long time. Lately he has turned into someone else. Don't get me wrong, he still has lots of moments where he is as sweet as can be, and so fun. WHY DOES THE KID THINK HE NEEDS TO RUIN IT BY HITTING? He hits everyone, well anyone who tells him no or anyone who makes it so he doesn't get his way. I don't want to be "that mom" with the out of control kid(s) who everyone dreads being around. Brooklyn cries at least 5 times a day about getting hit, its getting old. I need help! He goes to time out, and has to say sorry, but I don't think the point is getting across... We just started putting him in his room for 2 minutes every time he hits and that makes him really upset, maybe it will help. Well I guess that's about it. If you have tips or advice, I'll take it!