I quite understand that all. Info is permanently lost. But what the problem now is, the memory card is not discovered by my phone even when I used a card reader it was not discovered as well.
For more clarity on your situation, what phone do you have and which version of Android is it running?
This info can help determine just what suggestions may or may not apply.
-- Was this microSD card set up as Portable or Internal?
This is really pertinent. If the card was still Portable (its default), than the card also retained its original file structure (either FAT32 or exFAT). If however the card was reformatted as Internal, this results in a very significant change to the card's file structure. The file system is ext4, the same file system that your Android phone's internal storage is using, and just like the internal storage media it gets encrypted. That's an important aspect, both the phone's internal storage media and the microSD card media are in parity because at that point both are now set up to use the same file system and encrypted directly to the phone itself.
Assuming the card was set up as Internal, than also assuming by 'card reader' you're indeed referring putting the card into a card reader that you then put into a computer, because the card is now using a different file system and is encrypted, that card will not be detectable and will not automatically mount. Keep in mind that neither Windows nor OS X will be able to mount that card at this point, it's set up to use a file system neither one supports as is and on top of that the encryption prevents any access to the card's existing content (the encryption key only allows that particular phone unrestricted access).
Try this -- remove the microSD card from your phone and then turn off the phone. Start it back up again normally, leaving the card removed, and then try inserting the card back in place. Hopefully it will mount up automatically again and will be back to normal.
If that doesn't work out though, something could be wrong with the card itself. When it was originally left as Portable, it was still usable as a transfer media between different devices, when Internal however if you ignore all the warning messages and just randomly removed the card, that could increase the chance the card was corrupted. (When Internal, a microSD card is essentially changed into being another internal component to the phone itself. The phone's internal file storage media is virtually merged with the card's storage media.)
If the card no longer mounts itself automatically, you might try going into your phone's Settings menu and go to the Storage menu to see if the card is at least detected there. If so, use the indicated options to reformat the card (using the appropriate Portable or Internal options) This of course wipes it clean but it might also return it back to usable condition (if the file system was corrupted in some way).
Not knowing whether you have a Windows or a Mac, even though the card doesn't mount itself automatically at this point, that does not necessarily mean it's not actually detected by your computer. Use the Windows Disk Management utility or the OS X Disk Utility and see if the card media is at least showing as a detected volume and reformat from there (opt for FAT32 or exFAT, don't use Window's NTFS nor OS X's APFS)