German memoirs are often problematic due to the fact the authors will try to downplay the bad parts, and uplay the good experiences. Something like Kurt "Panzer" Meyer's book "Grenadier" is thus exciting, but full of fabrications and at times disturbing evasions of the truth. So instead, let me point you to a few good things to read, which don't fall into that trap.

"A Stranger to Myself: The Inhumanity of War: Russia, 1941-1944" by Willy Peter Reese: This is perhaps the most honest memoir of WWII you'll find from the German perspective. Because Reese died and the book was published from his writings decades later, you see none of the evasions, half-truthes, and outright lies of many others writing of their experience, and instead a forthright accounting of the barbarity, and his own complicity. If you're reading just one book, this is it.

"Soldaten: On Fighting, Killing, and Dying" - From transcripts of German POWs recorded during captivity, another work which is quite honest about their experience, unlike most memoir writings.

""The Good Old Days": The Holocaust as Seen by Its Perpetrators and Bystanders" ed. by Ernst Klee, Willi Dreßen, and Volker Riess: Pretty much what it says, a collection of Holocaust accounts by those who did it and those who saw it happening. It can be quite brutal at times.