I can identify with a lot of the behaviours you describe particularly knowledge of sex, very young and frequent masturbation, and 'playing' sex. I was a victim of CSA.
The flashback could well be a helpful indicator and sharing what you have posted here with T would definitely be a positive step I think.
I have had to take a step back from CSA talk as it has been too difficult so it is important you address it at your own pace and when you are ready, but remember T is qualified and there to help