It's rather hard to find an English translation; there is one [among a lot of other documents of that era] in Tryntje Helfferich: The Thirty Years War: a Documentary History.

Peter Hagendorf wrote a [retrospective; he wrote it all in 1649] diary of his rather extensive soldiering during the 30-Years-War [the diary covers 1625 - 1649] - for both sides.

There is some really dark humor in it; one believes he takes sardonic pleasure in retelling some of his misfortune.

It is lamentable that he didn't include how he went from mercenary without a job after 1649 to becoming judge and mayor of Görzke, Brandenburg.