The holidays are a time to give thanks and celebrate what God has done for us. As you focus on giving thanks for the true reason of the holiday season, you will begin to enjoy more and stress less. You deserve to have a great time during the holidays and not allow past issues to get in the way. The amount of joy or stress you experience is in your control more than you realize.
If you two just made things official a few weeks ago, the holidays might not be the best time to introduce him to your parents, let alone your entire extended family.
If he feels uncomfortable doing Christmas dinner with a bunch of people he's trying to impress, let him off the hook and wait for a more appropriate time to introduce him to everyone.