Sounds like you haven't yet come to an agreement about how to handle holidays and special occasions. Without that agreement, drama is sure to arise whenever a holiday or special occasion comes up. It also probably won't help to try to negotiate special occasions when one is already at hand. By then it's an emotionally charged topic and bound to become a contest. The negotiating has to be done well between special occasions, and the agreements will need to be very specific (e.g., birthdays are just for the two of us, but Christmas can include "x" amount of time with the other guy).
Since you guys are both strung about as tight as you can go, all negotiations will have to be done with great care. Remind W that a compromise involves give and take, so both you will need to give up something you want so the other person can get something they want. You may need the counsellor to mediate the discussion about holidays/special occasions.
It's unfortunate that things are as strained as they are, but they'll probably continue to be strained for quite awhile. Take what consolation you can in that factor, as it's bound to come into play whenever the least opportunity presents itself. A birthday is definitely one of those opportunities.
Love means never having to say, "Put down that meat cleaver!"