Germany's healthcare system doesn't have a long term problem with funding. From DW:

>Germany's understaffed and over-bureaucratic hospital system, where doctors and patients have for many years complained of too many financial incentives to "over-treat" patients, has resulted in long hospital stays, unnecessary operations and unnecessary antibiotic treatments, among other things.

Aside from hiring more staff, cutting down on bureaucracy and unnecessary treatment would save money. This is of course leaving aside that €5 billion per year on Ukraine is a drop in Germany's federal budget and directly increases Germany's security.