The shock has worn off

Well the shock of my biological dad showing up after 20 years has worn off.  I wish it hadn't to be honest.  I liked that feeling A LOT better.  Now I am to the angry and frustrated feelings.  I don't like those feelings ever but especially not during the holidays.  But I can't ignore them:(  I can't unfeel them and I find myself withdrawing quite a bit.  I am angry not only at him but at my mom, my grandparents and my aunt for hiding things, lying and for the trust in the relationships being destroyed.
  I did finally write him and did after a few days get a letter back. I know I should have no expectations but of course I did at least some little ones.  I thought he would say he was sorry and that he wished he could undo all that he had done, that he was sorry he had missed out on so much with me, but nothing:(  BIG fat nothing:(  WOW a punch to the gut:(
  I think it hurts more that my grandparents and aunt are so willing to just jump back in and that they were willing to not tell us kids:(  That they were ok with him just wanting to leave us out.  That they had lied about things that had happened in the past or that they let us believe things that weren't true.  That they are telling him personal things about me and my brother they really have no buisness telling him without talking to us about it.  My grandparents are flying up here to spend thanksgiving with him, I am trying to have the holiday spirit and say good he will have family for the holidays but then other things come to mind like they never fly up for holidays with us, they didn't fly up for my wedding but here is a man that disappeared on them for years and years after ripping them off over and over and causing hell in their lives and they fly on up.  I know it is their son and I am trying to be understanding but I feel hurt and betrayed:(
  I don't know what will happen.  I am trying to be understanding and look at it from others points of view but it is hard and of course there is a lot more to the story and it just brings up a lot of the old hurts that were never acknowledged.  So trying to just concentrate on the good and the awesome people in my life for now.
   I am trying to just be thankful for all the good in my life.  Even when it all is crashing down around me in every way I will find some good.  LORD I will find your good in this.