HELP!! DD just deleted the wrong partition !!

i am sure that i selected the correct partition for deletion in order to make room for the next partition which was almost full. executed deletion. I am sure the correct partition got deleted. even the new unallocated space was to the left which means i deleted the correct partition. then i resized the next partition which was almost full (which is a partition i wanted today to back up) and DD told me it needs to reboot. Rebooted , and it gave some errors and ended. After that the deleted partition is back in place and the partition that was supposed to be resized dissappeared !!! no unallocated space, the deleted partition is back and takes up the space of both partitions now !!!

How can i retrieve the partition (or data) of the partition that i tried to resize and now dissapeared ???