You are conflating blame and agency. Suppose Brittney Higgins gets really drunk and gets raped. It is 100% the fault of the rapist. That does not mean that Brittney Higgins would have been safer and would have been wise not to have got drunk. It is wise to advise young women not to get really drunk but incorrect and unwise to day that if they get drunk it is their fault if they get raped. Same with having your car stolen after you leave it unlocked.
To take up your position that it would have been better if I had spotted the plane, it would have been. But the pawnee was faster than me and approaching from above me. You are actually suggesting that pilots on final include above and behind them in their scan. I don't think pilots actually do that. It is quite likely that my view of the aircraft would have been shielded by my wing. To continue the analogy, I think that the situation would be more akin to someone not being drunk at all and being raped.
Which leads me to your comment that the tug pilot probably saw me, a comment that you apparently stand by. If the tug pilot had seen me then he would not have flown up beside me. And, being a low-wing aircraft it would not have been able to see me from above.
When you say that you told yourself that it was your fault when someone cut you off on downwind, that is good, because it means that you mentally take responsibility for things that are not your fault and thereby make your flying safer. The issue of how much one should blame oneself.
Blaming oneself and one's mental health is actually an interesting area. If someone is depressed and/or anxious, they tend to blame themselves for things that are not their fault. By having the person look at situations more objectively and see that things that were not their fault were not their fault, they can become less anxious and depressed, because they feel better about themselves and their ability. Conversely, if someone decides to mentally take responsibility for everything that happens to them, they can feel better because they are less angry at other people and they have a greater sense of agency. The best situation can be where someone both lets themselves off the hook for their mistakes because they are only human, and takes responsibility for everything that happens to them. These ideas are completely contradictory but co-exist perfectly well. You know how sometimes you feel useless and at exactly the same time you know you're not? Same thing. No need to fight either state, they can both just co-exist.
You need to be more sophisticated with your idea of "your fault" and "I make mistakes too". The idea of agency vs. blame might help. If your ideas become more sophisticated, your communication might be too. If you say "that was pretty much your fault because of inexperience" when the idea you are actually trying to convey is "that was not your fault but if you had a better scan, you still could have avoided the situation. But, I think that that give you too much credit, TBH, because you still apparently stand by the statement that the pawnee pilot had probably seen me. That's just bizarre.
Also, there is the issue of the term "airmanship". As someone else here stated, the term causes problems. A similar problem occurs with the term "judgement". If a flying instructor tells a student that they are doing to teach them "judgement" then it causes offence and decreases the opportunities for learning. If a flying instructor tells someone that they are doing to teach them "risk management" then things go much better. It is better not to use the term "airmanship" and to use more specific terms, which can be operationalised, like "visual scan" or monitoring the radio."
The same problem comes with blaming "inexperience". I have already remarked on your use of this term. My view is that, as Forrest Gump might have said, "Inexperience is as inexperience does". In other words, if I was flying a normal downwind and the tug pilot came within 30 m of me (after having probably seen me 🤪) then I was actually being more "experienced" that he was, regardless of our hours.
If part of your job is communicating to others at Caboolture about safety then you need to get better at it.
As for the timing. The incident occurred on Saturday 3 August 2019. It was reported either on that day or the 4th because I got a reply from the glider federation on the 5 th saying they were going to tell CASA. Had you begun at Caboolture yet?