Though he doesn't answer you he still sees the messages so say sorry, tell him how much you love him, think of him and can't live without him, and he should forgive you and you won't repeat the mistake and all kinda things so I'm sure his heart would melt after knowing you have planned a future with him and all!
If someone is mad at you it is probably best just to leave them alone for a while. Never blow up their phone with text messages. You will most likely make them even more angry. Give your boyfriend some space, and when the time is right eventually he will come around.