+ 1 for liquid antimatter. I don't know how you were using it, but it is much more effective than regular ai3 for cash, at least when I used it. With a normalized win rate of 20% for FG's, you shouldn't have too much problem. I suggest you give it another try, but this time red the thread carefully and learn the strategies, which gods to skip etc. Sometimes you need to skip 8 gods before you reach a playable one. I don't recommend you to farm ai4 - the rewards are too low for the time it takes to kill them.
For silver/gold, JMZ classic is a good deck to use, but it is compleatly upped. I'd stick to FG's, perhaps farm with liquid antimatter untill you have enough money to upgrade 6 supernovas, 1 siluarian dragon, 4 electrum hourglasses (if you get these cards from FG's, don't sell them). Then you can farm unupped 4 shards of readiness from the arena to build a partially upped instosis. Once you start farming with intosis, you should be able to finish upping it in a day, and obtain enough money for another fully upped deck in another day.
I don't recoment Rol/Hope beause the cards it uses are difficult to reuse in other decks and pretty much fixes the immediate future of your elements career to aether/light. Instosis' spernovas and electrum hourglasses are much more flexible.