Can anyone give me some advice?

Your dad over reacted but he cares about your or he wouldn't buy you a surprise cake. I have never had my birthday celebrated so you are many times luckier than me. If you still want to cry, let me give you a big hug. Mind you that I haven't had a bath for 4 days. Maybe I should now...

Ok this is going to take a while to get over. First things first, you need to let your dad cut a cake. Not any cake, I mean a fresh cake, this bad boy needs to be baked that day and have the smoothest untainted icing on it. No knicks, no bumps, a perfectly iced cake. The cake needs to be moist, best bet would be getting a fresh chocolate mud cake, one that when your dad cuts the cake half of the cake will be stuck to the knife. Man there is no better feeling. Actually first buy that fresh cake and cut it for yourself, indulge that feeling! You need to understand what you have robbed your dad of. The whole suprise thing he was on about is 100% fake, its a cover up, that man wanted to cut that cake. Please note this will not completely heal your dad, he promised himself that he would be cutting that cake, imagine having someone take away a personal promise to yourself. You need to let your dad know how sorry you are, let him know after he cuts the new cake you dont want him thinking that it is just a sympathy cut. Let him know people go through the same struggle everyday and there are people out there to help him get through this tough time.

Im sure you have always seen your dad as a strong figure in your life and you are probably in shock after seeing him so weak and upset but as you know 'the first cut is the deepest'. Good luck.

Get over it. A lot of children don't get anything for birthdays. Consider yourself very fortunate to have a roof over your head, food on your table and a family that loves you.