On the forums you vibe as having a strong 4 fix to me, and as I've said to you, I expect with how you express yourself here people will struggle to see you as a 9. I have the impression you can be everything to everyone so people will see you however you present to them, which will be changeable and able to fit a fair number of Etypes. Getting to know you over time in person left me being unable to see any other type fitting you as well as 9, however without knowing you off the forums I would have a hard time seeing you that way.
You don't talk about the things you avoid here, or how you avoid them and numb yourself out, for the simple reason that you are avoiding them! What you do is express yourself in a style that a non-4 would likely consider 4 expression, and a fellow 9 would not relate to the darkness of it all.
You don't show scepticism like a 6 would, nor do you show the need to deal with disturbances when they come up, I don't rule it out entirely as your head fix, just most unlikely, I expect 7 fits better, this is after gut and heart. Being tripple withdrawn is my issue with a typing of 945.
Short of pulling out Enneagram books
this is the best write up I've seen on E9s.
In terms of 5 v 9
this post pulls together the clearest points I've seen on spelling out the key differences between the two types, in short a 5 will see what is going on and detach to observe, a 9 will see then numb out reality and pretend it's not happening. If you relate to 5 I would be a little surprised, I don't see you detaching and observing. You are intellectual, this isn't to be mistaken for 5.
Of all the personality types, Nines have the most difficulty identifying which type they are because their sense of self is undefined. Average Nines have little sense of who they are apart from those they have identified with; hence, they are usually at a loss to know where to begin to find their type. (As we have seen, either they think they are Fives or Twos or they see a little of themselves in all the types and make no further effort at identifying themselves. If they have no guidance, Nines in this predicament usually shrug their shoulders and give up on the Enneagram and more important, on acquiring self-knowledge.)
Anyhoo, you're such a freaken 9.
ETA: Something I just realised, on the forums I don't relate to you, in person the way you react under stress is so easy for me to read because there are no distinguishable differences to how I react myself.