If he loves you, he will understand. (If he loves you, he might also want to kill the person responsible)
If he's the right guy, he'll be much more upset about the person who did it to you than he will be at you. I've made it a point to tell my partner, and he was just upset that he couldn't protect me. If he cares about you, he won't get too upset at you about it. If he needs time to think about it, give it to him and tell him your reasons later :)
You might not want to do this alone is all I can add.
Good plan :)
He will most likely be more hurt for the fact that you waited so long to tell him.
I am so sorry that that happened to you. And it sucks dealing with it all because of that incident. I hope whoever did that to you goes away for a long time.
That being said, I am trying to place myself in his shoes as being a reasonable level-head male as possible. It will definitively will be hard for him to hear that this happened to you and he will feel so helpless that he failed to protect you and keep you safe. He may blame himself and whatnot. Totally normal things to think and feel in that situation. He will also feel extremely hurt, sad, betrayed that you didn't tell him as soon as it happened. You are an awesome person for being strong and having a survivalist mentality. I am pretty sure you know this but I am going to say this anyways. The rape was NOT your fault. Not even .0000000000000000000000000000000000000000000000000000000000000000000000000000000000000001%