Sorry to hear it didn't go well. It could be that it simply didn't work for you or that the block wasn't correctly placed - there is no way to tell after the event.

I had a lumbar sympathetic block shortly after my diagnosis and mine didn't work from a therapeutic perspective. The block was clearly correctly placed in my case - it simply didn't give me any therapeutic benefits. It is becoming apparent from the more recent CRPS literature that the view is changing a bit on these blocks - they are not regarded quite so much these days as just such an effective treatment option as they used to be.

I guess you have to be guided by your doctor's opinion on the benefit of doing another one. If he feels it is worth it, you may get a better outcome which would be great. If not then at least you have tried but it is probably important to accept that there are lots of people for whom they don't provide a therapeutic benefit. If you don't feel ready to have another one done next week - ie if your symptoms still seem worse then why not ask if the next block can be postponed until your leg has settled down a bit. In the UK (even going privately) they would not do the blocks so close together - they wait a number of weeks in between to give them a chance to assess the effect. Best of luck.