It is eerie how similarly I felt about my own T when I terminated last fall. I'm so sorry you're going through this. It's awful. It's all-consuming hurt.
Based on my experience, my suggestion would be to see consult T, or really any competent T, as soon as possible. You don't have to open way up right away. But you are really going to need to process this, and while friends and family that you might trust with this can offer kindness and sympathy, no one's going to get it the way a T will. The T I settled on in the interim between termination and slowly starting back up with T was largely there for me to (1) continue to manage my depression while I figured things out and (2) to figure things out. I was up front with Ts I interviewed that this issue was fresh for me and still in process and would probably be a main part of my interaction with them. A decent T will get that.
I have a pdoc, too, and she was also very kind during that period. I didn't know her as well, but it helped SO much to talk to someone who got it, and who was willing to step up and say that she'd step in as that point person if I was ever a danger to myself, which I was at that time. Again, I'm not that close to her, but I needed to talk, and I needed to have that lifeline there because I had suddenly been thrown into a very dark place in terms of my mental health. You don't have to worry about doing the therapy "work" now. Getting a T or pdoc or someone like that ASAP is a way to do some basic emotional self-care. I understand it's daunting, and I understand this may not work for you the way it worked for me, but it's my experience. I didn't want to open up either, and I will admit that it was sad for me seeing a new person at times. But it was much better than withdrawing and trying to go it alone.
As for sending an angry message, you're probably right to wait. I did send T one short, angry message when he had decided to terminate me after weeks of deliberating -- that was because there was a lot going on that day; found out my stand-in grandfather was dying the same day, and I sent T a short, scathing letter about how I needed him NOW and he was running off and hiding under a rock. I don't particularly regret it because I was so overwhelmed that day I don't see how I could have held it back.
Later, I sent him a longer letter. I took time to write it. It did sometimes feel like I was wasting my time on him. But I had already written many letters I didn't send (very therapeutic for me -- and some of them so bitterly angry that even now that we've reconciled and started working together again, I won't show him), and finally, pulled together my thoughts enough to write one that said the things that I felt like I needed him to know, AND that I felt ok saying without getting a response. I was able to filter a lot of the anger out of it and leave it at the things I felt I needed to say to move on. It did help me.
So, it's not overkill. Or, if it's overkill, them I'm right there with ya

. You really have to do what you need to do to feel better. Try not to judge yourself too harshly right now.