You should first restore your partition /dev/sda2 with testdisk. Then, you need to assemble a RAID1 array from it, using mdadm (mdadm --assemble /dev/md1 --run /path/to/your/restored/sda2). Then, from this RAID array, you'll have to scan for LVM volumes (vgscan), and enable logical volumes in the "main" volume group (vgchange -ay main). Only then you should have access to /dev/main/root (which you can mount anywhere, it's an ext3 file system) to get your data back. Of course, all this assume that you haven't damaged the partition, itself, but just touched the partition table