Why is my 'd' sound always triggering confusion when talking to native speakers?

I’ve been practicing my Telugu daily, but I keep getting corrected when I try to use words like 'dāri' or 'deśam'. I think I'm failing to distinguish between the dental 'd' and the retroflex 'ḍ'. Is there a specific tongue placement exercise for Telugu retroflex sounds that actually works, or am I just overthinking the apical vs. sub-apical positioning?