It can be a very slow process which requires a lot of patience unfortunately. I broke my ankle if four places and had to have plates and pins to fix it, that was a year and a half ago - I just had more surgery 3 months ago (having physio now). My break and the subsequent problems was just unfortunate, not typical.
First surgery I had was in December 08 and it wasn't until about april/may I was walking without crutches. You just have to be patient with it (hard for me, I can relate). As Squad says (and he should know) just keep an eye on the toes and get someone to press on them every now and then to see if the colour returns quickly as it should.
I cannot imagine how much pain a shin break would be, I sympathize. I would mention the amount of pain your in and difficulty your having with regards to going to the loo etc.. when you see someone - but to be honest they probably can't do more than they have for you. It won't seem like it now but I promise it does get easier to get about and they pain does ease off. I was in total agony for about a week after my first surgery - I cried non stop and couldn't do anything on my own. I shook uncontrollably for the first day or so with the pain and shock of it all I think.
Hope you feel a bit better soon, it will ease. And I am sure you will get physio for the injury after your cast is removed - its a slow process but when you do start to make an improvement you will come on leaps and bounds I am sure.
Good luck, let us know how your doing.
Greedyfly