I knew other people felt this way (now, after finding out why I did) but I've never seen it described so accurately! I'm not saying we are 100% going through the same thing, but I'd give it a 90% chance here based on how much this describes me.
for me, it turned out that I had c-ptsd from chronic overstimulation and emotional/medical neglect as a kid - just enough to go under everyone's radar. I am autistic, but my parents were in denial, nobody really "knew" or confirmed it because I was forced and eventually became able to "act normal" despite still being a big bullying target and a little weirdo in private. but beyond the social aspects, these symptoms you've described and what I've felt turned out to be a reaction to something I've forgotten long ago. I was physically looking fine, emotionally seeming okay on the outside (because I shut down outwardly rather than melt down), but I went through repetitive unaccomidated experiences that hurt me in the long run. but I didn't have a big traumatic event I could point to. the physical medical neglect I experienced later was unrelated and more nuanced. and I was surprised when I was working with my therapist and my biggest issues were not single events - but tiny little things that built up over time, every day.
the only thing that's helped me actually stop them has been EMDR - but it is a strooong trauma therapy. it's not scary - people without c-ptsd do pretty hardcore processing routinely that's just like it during REM sleep, it's part of dreaming - but I really could only do three sessions before I needed to stop and process how I feel about my life now. but I can walk into school's now without any of the same physical or emotional issues I was having! but before it always felt both nostalgic and bad, like at best exposing myself in a controlled setting.
I'm not trying to say you're autistic or have c-ptsd, but that's what it ended up being for me. C-ptsd gives you triggers that make you feel like you have the trauma event of PTSD, but unspeakably so. the best comparison I can make is PTSD is a broken leg you can put in a cast and mostly heal up, while C-PTSD is getting a hammer to your leg every day until it eventually cracks, but you don't even notice it anymore. all you know is that hammers make you feel sick and you're protective of your leg now. triggers feel more abstract and unable to pinpoint. I didn't realize why my triggers were so intense before memories resurfaced about them after EMDR.
so if it's intense, I wouldn't nessecarily say you NEED EMDR now, but talking with a trauma therapist isn't such a bad idea. I do believe c-ptsd is underdiagnosed, but also understudied and poorly understood. so I think it's worth asking yourself how intense it is, and a lot of people don't know they deal with it. but you're not alone! I deal with it too