Dex in Emo corner?

1. My friend's (call him S) high school friends came to my dorm to say happy birthday to this S guy with a birthday cake. He actually had an appointment, but it's not really urgent. In fact, he could ask for permission that he would come late to that place. He actually came after my other friend (C) called him, but S looked like he's not interested, like he prefer his previous appointment, even to the point that he left before those three guys lit the candle and asked him to blow the lit candle. Finally, after S left his high school friends those 3 gave the cake to me and C. Personally, I feel a little bit annoyed to him cause his friend had come from another city bringing cake and one of them hit a sharp iron nail on head. But When I think about it again, it's not good to be annoyed to S. Dunno why, but anybody can give me a suggestion about how to talk to him properly? cause if I'm still annoyed at him, I and my friends won't be able to bring ourselves to make a surprise party...

2. I feel really angry and mad at myself for not being able to celebrate new year with my dorm friends!!!!! to think that there are many IRL OTP moments happened makes me really sad and to think I missed it too here, I feel that I'm such a bad friend for everyone here and there T_______T
will you forgive me for not coming here on new year and anybody can give me a suggestion not to sulk about it too much?