Can you experience the stages of trauma 20+ years after repressed but somewhat continuing trauma?

I'm brand new to sharing like this and also brand new to the idea of having C-PTSD after being a victim of childhood trauma given to me throughout my entire life by my grandparents. If this isn't the right place for this I apologize, please let me know where it should be posted if so because I really need guidance. I'll try to be brief in my background information so I can get to the question, but I believe this needs some context.

I've never liked my grandparents and never thought of our relationship as anything more than them "investing" in me so they could be the ones to take credit whenever I accomplished something. They're very wealthy and had successful careers, but money and the "respect" they believed they unconditionally deserved was always in the forefront. When they actually did share their wealth (be it a present or if another family member was struggling), there were always strings attached or conditions to their giving. From the minute I was born I never received any child-like presents like a toy from them, I received bank bonds in order to pay for college because my future was the most important. Throughout my life they always made (and still do) unachievable expectations (because nothing would ever be good enough even if achieved), backhanded comments, questioned my every decision (because what they felt I should do was the right choice), or straight up insulted me. I was forced to perfect a "mask" to hide what I really felt about them at a young age (which now unfortunately automatically turns on when I'm in any stressful situations) and taught to laugh the abuse off by my parents and other family members. I do not have a single positive memory with them in it. When I was diagnosed with generalized anxiety and depression at 14 years old, they saw it as more of an inconvenience. When my college bonds ran out and they started paying for the rest of my college out of pocket, I told them to stop after one year because of the unbelievable pressure of giving them my transcript every semester to be scrutinized, the required phone call once a week that consisted of them insulting me and questioning my major, and all the other "conditions" that went with their "generosity". They took that as an insult and my nana screamed at me for almost two hours starting in the middle of a restaurant and then continuing outside when excused myself. My dad's generational trauma from them passed down the feeling of guilt and obligation to family and basically facilitated this abuse as he forced me to have a relationship with them.

In summary, because of the consistent nature of my trauma and everyone in my family boiling it down to "that's just how they are" or "they mean well", I never viewed the way my grandparents treated me as abuse. I talk to them less often now because in the past couple years I put my foot down with my dad and only call for holidays, but even in those fleeting conversations they sometimes sneak in something insulting or critical. I only discovered less than two months ago that my tumultuous struggle with anxiety and depression was actually caused by C-PTSD from the repressed childhood trauma that I constantly endured from them. Ever since this realization, I have been going through what I can relate to the stages of trauma: extreme anger that I don't know what to do with, constant 24/7 anxiety and hyperarousal, depressive episodes, etc.

My question is this: If you have repressed childhood trauma that has just been realized (I am now 27 years old), is it possible to start going through the stages of trauma 20 or more years after it started? If so, what are ways to cope with the sudden uncontrollable and overwhelming emotions and feelings after repressing for so long?

Thank you in advance.