In case you do not get travel insurance from an insurer in your current country of residence, you may want to have a look if you can find an insurer in your previous country of residence that does not require (a) a domestic place of residence, and (b) a domestic health insurance.
Since you are a former resident of Germany, you may get health insurance from there. Finding a suitable provider can be tricky, as such things tend to be hidden in the fine print. To give you a start, the ERV insurance company seems to be fine (according to paragraph 2 of their terms and conditions) with any place of residence in the European Union.
Another possibility would be to get a list of travel health insurance providers and look through their terms and conditions. For example, you should be able to find a whilelist of travel health insurance providers for German applicants for Russian visa on the web.
(Note that I only mentioned ERV above because they were the first suitable provider that I could find. The link leads to their T&C document).