Oh Ambra,
I am so sorry this has happened. Please let me be the first to say you are NOT being a wimp. Unwanted touch is a huge boundary violation, and when it's by a boss, there's intimidation too. In the U.S., it can easily be considered sexual harassment.

From a purely practical standpoint, I strongly encourage you to document what happened. You can even just email yourself - just put it in writing with a time and date stamp. It would be better to email your boss and explain that though you know it is the holiday season and he was probably just being friendly, you were very uncomfortable with his hugs and would appreciate if he refrained from doing so again...(etc.)

Now to the crux of your question. You would not be selfish to text or email. You would be asking a care provider, with whom you have an arrangment, for help. Your T may not be in a position to help and could say she was unavailable. That would make me very sad for you, but it wouldn't take away from the fact that you expressed your needs. On the other hand, she might be able to give you some help processing this so that you indeed recognize that your boss is the evil party and you have NO REASON to take anything out on yourself. I am quite familiar with SI urges, but it will do you more harm than good so please don't do it.

Offering you safe and virtual hugs.