External Hard Disk accidentally formatted >.<

Hello,
i got a problem here.at first,my computer didnt detect my external hard disk,it was solved after i assigned the letter but unfortunately,it formatted.all my important files lost.isn't the solution format it to FAT32 file system? but i dint found FAT32.what i've found are NTFS and exFAT. i choose the exFAT one but it doesnt seems like all my files will reappear in the external hard disk. hopefully someone can help me overcome this problem. T.T