TBH you are unlikely to have taken too much; though I would suggest getting hold of a set of small electronic scales; they can’t be more than $5 or $10 where you are.
If you have other hobbies such as art / electronics it is less suspicious to order other related items at the same time there are probably loads on Amazon and way too many transactions for fed to bother with small stuff.
Bear in mind too the size of a dime is not as familiar to us Europeans.
Even if we know what one is due to the lyrics of pop music from the USA and TV/movies, coins of a similar value in Europe were once slightly larger plus the metal in them changed since the 1990s (copper is useful for electric wires so the copper coins became worth more in metal than their face value!.
Not long after many countries adopted the Euro. Thus ravers who grew up then do not use small coins for judging weight/size of stronger powder drugs as there were so many changes it was easy to get confused and risk an overdose. [The Euro notes were better and more robust for snorting tubes than local British currency].
Many nations now have the Euro as a main currency (those which do not can still trade in it) and some have stopped issuing the smaller coins or shops won’t take them although this does mean the coins are more standardised with regard to size/weight. The Germans do often use a €0,01 coin (one euro cent) as a size indicator.
