Querries are getting slower

Im a begginer in Mongodb, thanks for assisting.

My current config, everything is in local same computer, i dont have much space that is why im using zstd:
journalCompressor: “zstd”
blockCompressor: “zstd”
compressors: “zstd”

Currently in database 151 million document and i need to add 500million more…
my data is like this
_id : mail@mail.com has nested object called actions.

What im doing:
Read a txt file do some regex and after matching it sent it to mongo with a updateOne function of mongo upsert is on and also im using addtoset function of mongo db basicaly im checking if mail exits in my database if exists im checking actions object if the new action is not in it im adding it to that object.

My Machine
im on a 3200 read 1800 write ssd, its my local data logging database, my machine has 16gb’s of ram and a 9th gen i7