Hi Flossy - this is all really stressful so it could be that you are really tense and that is making your back pain worse. It might be worth trying a relaxation CD - I got a free one from my local Maggie's Centre (they might be able to post you one), but they are quite easy to buy. Can't do any harm, right?
Also, I wanted to say that I had to do the anticoagulant injections too - twice actually because I had two rounds of surgery. It is not much fun, but you really don't want a blood clot on top of all this. Stick with it, it'll be over soon enough.
Like everyone says, try to take it easy, give yourself time to heal and don't rush things. Week by week you're getting better and it won't be long now. Good luck x