I would try staking it upright and heeling the soil around the plant. They dont seem to repond to well to hard pruning. it would be better to prune it straight after flowering.

Yeah thats what i thought but I was hoping for a miracle cure :)

sorry :o)
I had a buddlea that did the same thing 5 yrs ago. I used my daughters skipping rope and a huge wooden stake. it has survived and grows straight now.