I feel you. I live in Germany and we have many people whose mother tongue is a slavic language here and they all get it wrong to some degree.

I'd still like to encourage you to put some energy into getting it right because this mistake is very confusing for native speakers of a language that makes the distinction.

I cannot tell you how often I was listening to someone telling me a story about the thing where I sat impatiently waiting for them telling me which particular thing or person they ment only to realize they were not talking about something particular at all.