求一篇英语道歉信~内容是关于没有参加生日聚会的

Dear xx

I'm writting this letter to apologize for not attending your party. I've been so traped with my schoolworks these days that I forgot your birthday. I feel sorry and mad at myself.Hope you could understand and forgive me.
Happy birthday dear and I wish you all the best in following days
I'm looking forward to seeing you soon.

yours xx

(用的是写给朋友的口吻，比较随意，希望能帮到你)