Is there a way to see how many amenity=bench I have created?

Definetly! You can use SPARQL to query the database! Kinda new to the whole thing, but I think this at least shows how many benches you have edited as the last person.

SELECT ?user (COUNT(*) AS ?count) WHERE {
  ?bench osmt:amenity "bench";
                osmm:user "Ludrol".
}
GROUP BY ?user

LIMIT 2

Which returns 60 :)