GPT partition deleted and unable to mount disk

I accidentally deleted GPT partition table. Now I can't mount or see any data on my HDD. I tried every possible solution on internet instead it got worse. There is no back up. On disks this is what it shows When I run TestDisk it shows complete partitions and I am able to list all files. I don't want to mess up any further. Is there anyway that I could mount my drive and its partitions? **EDIT** I can't remember what exactly I did to delete partitions as it was months ago. I lost grub and tried to recover using boot-repair and gdisk. So far I have tried testdisk gpart. when I tried sudo gpart /dev/sdb, this is what I get