mrsmopp, maybe 'not much fun' but just take note that without this wonderful medical procedure you would die. So, just be very, very grateful that not only do you live in a time where this can be carried out, but also you do not have to worry about finding the large amount of money to pay for this operation.
You will not be allocated a Stoma Nurse, until you actually have stoma - you will probably met that person whilst you in hospital recovering from the operation. Amazingly this operation is now being done (in some cases) by keyhole surgery. Incredible - as removing largest organ in body. Where the op. can be carried out that way it brings down the time required for post-op recovering to just a few weeks instead of a few months.
Once you have recovered from the actual trauma of the operation, no reason for you not to be able to continue your usual activities, doctors will very much approve of your walking. Ileostomy Association (Ia), produced a quarterly magazine (well worth joining this Association), and people in that have written their stories of crossing deserts, deep-sea diving, climing mountains, etc. etc. after their ops.
For myself - the hardest thing I did was the first time after my my op., when I sat in front of a large audiance wearing the totally white uniform clothes of an ASA official!!!
I suppose that thirty plus years of having this bag on my tummy, it is just totally normal for me. Please do feel free to PM me anytime if you want to ask any specific questions.
Coming to terms with your illness is going to be the hardest part - the fact that it can be dealt with is just something to be thankful for.