PTSD? TW: Abuse

Hi, everyone! I'm new to this so I'll get to the point quickly.

When I was 8 years old, I was abused by a family member for a few weeks or months, I don't remember. Back then I didn't tell anyone and didn't really think much about the situation other than when I heard about things like that on the news or the radio.

Eventually, I got to an age where I realized I had to speak up but it was harder said than done until back in 2020 when I opened up about the situation to my mom. The guilty family member was kicked out. I decided not to open charges because I didn't want to relive the situation by talking about it in detail and saw a psychologist for the next few weeks and throughout this time. I always feared that the family member in question would find me and harm me in some way for "ruining" his life. I would see him in places where he couldn't possibly have been and I'd confuse certain strangers for him but never said anything. I also avoided going to the place where the abuse happened, I'd constantly have dreams about him and whenever his name was mentioned, I would disassociate which had never happened before. I now disassociate regularly and can't control it. My memories began to turn against me and bits and pieces of the abuse began to confuse me, I couldn't clearly remember what happened and what didn't or if it was really real.

He's been let back into the family since then and everytime I hear of him coming to family events, I'm always on guard. I can't look at him, say his name or even be in a room where he's being spoken about. Why is all of this happening only after I've spoken out? Why didn't it happen right after the abuse all those years ago? It feels like my body had a delayed reaction. I think it's PTSD but I'm not sure it works like that. Can someone please clarify.