Insensitive and unsupportive SO

 The thing is my SO always says that if I feel bad about something I can wake him up and we can talk about it.
I woke up at 5 am in the midst of an anxiety attack. The response I got was basically "I can't deal with this right now". I tried to handle it myself, but after 1 hour the anxiety hadn't passed, so I gently wake him again saying that I would really need to talk because I'm really struggling. 
He just started yelling at me about how irrational I am and how I should just let it go. He did this while having his back to me the entire time, without even looking at me. And now here I am, feeling that I really lack the support that I need. 
I appreciate that he needs to sleep too, but then why even tell me that I can wake him up and then get incredibly angry at me for doing so? All while I'm trying to tell him that I'm literally falling into pieces.
I'd like to add that this doesn't happen very often. But I got some really bad news about a family member recently. We live overseas so I'm just really stressed out. 
I feel this has affected my view of our relationship, am I overreacting? 
UPDATE: 
I did try to talk to him, and explain that I got hurt and that his reaction didn't help the situation. 
But apparently me telling him that he hurt me, made him upset and hurt, so now I'm the asshole..