It is probably not the advice you are waiting for...
Two options.
- Leave the whole thing as is, never play Elements again. Probably you will have a lot of free time. Play basketball or anything more active.
- Start grinding bronze arena again. Start with mono darkness then buy 6 photons, 6 sparks, 6 daggers and build a "free creatures deck".
Add 6 dragonflies, use Air as mark. Add 3 Azure Dragons and 2 Fog Shields, 1 Wings as well. Kill off 1 hp decks, skip anything having more then 7 hps. Roll ONLY for rares,
special rolls, you know. Always try to beat the top 5 guys, they net more money (that's why you add dragons...) Upgrade gnome riders, dragonflies,
photons and add 2 hope to the deck. You can also experiment with it, the point is to kill 1 hp decks as fast as possible, thus getting 40-50K electrum / hour.
Sorry, but really no chance to get back those cards. Sad, I know. Either quit or restart - there is no other viable and satisfying option.