In order to send my bitcoins to my darknet marketplace account, I used electrum.
But I didn't download electrum off of Tor, I used my usual browser in order to do that. Is my security somehow compromised because of this?
(Sorry I'm new to this stuff.)
Electrum and other "light" wallets are extremely bad for anonymity or privacy. For more details see https://www.reddit.com/r/DarkNetMarkets/comments/3353ae/opseccomputer_folks_gotta_stop_saying_use/
Please read through the sidebar at /r/DarkNetMarketsNoobs and take the time to answer all your questions over there before you put yourself in further danger.