I AM SORRY I DIDN'T COME TO YOUR BIRHDAY PARTY LAST NIGHT BECAUSE...
3 . I am sorry I didn't come to your birhday party last night because I was too busy.(wish)
...
I wish I had come to your birhday party last night
3 . I am sorry I didn't come to your birhday party last night because I was too busy.(wish)
...
I wish I had come to your birhday party last night