Hi Liam
It would be impossible to know what you did based on your description and I don't think you will successfully improve your description as so much happened in the session. Yes you could have an ankle sprain but due to the high impact nature of your sport you could have done something else. Given the long delay in onset of the pain my guess is that you did something to one of the soft tissues in your foot. Often we can keep going as with all the adrenalin during the session we are hyped up and suppress our pain response. In fact we are able to unconsciously suppress pain with severe injuries (battle ground injury phenomenon) to an incredible extent - so you can't rule out doing something more severe.
However being unable to WB on the foot due to pain and given the amount of pain you had I think you really need to get it properly checked out. You could potentially do a lot of damage if you have something like a fracture.
BTW the icing probably didn't make things worse - probably the pain just got REALLY bad at that point so more coincidence - good thing you did ice it anyway.
I am not in Oz so I don't know the current fees you pay but as I recall organising an Xray (which you may need just to rule out anything like a stress fracture) costs nothing and so getting it properly diagnosed shouldn't cost you that much.
And hey...you only get one body in this life.