I am the flip side of you getting heaps of RP. I stopped playing Splinterlands for several months and only came back due to the new reward system.
Firstly, if you are still using starter cards, you need to stop as the reward reduction is massive. Secondly, if you do not have the meta cards, you should start renting them as the rental market is very under-valued currently. Especially if you have fire focus, just get Yodin & some GF ranged cards and blast everything to bits. Lastly get enough CP to be in the Silver League, then you will see the reward chests flowing in like crazy. Wins in Silver League with a decent ECR can net you close to 2,000 RPs.
I wrote some stuff about this if you are keen to have a look. Just remember to set a daily rental budget and if you tight on DEC, only rent and do the dailies on your favourite splinters. My budget is 50 DEC max and mainly for the fire splinter. Yodin is OP in the lower leagues!