I make this mistake quite often and drain my energy capture rate. It usually takes some time to understand that it will not work out and revert back to focus on only one thing at a time. Today also the same happened. I was continuously using my Fire splinter to win the daily quest. Though fire splinter is the top deck in my collection, it is not necessary that it will work for all the battles. Sometimes, we might have to consider using splinters strategically.
I did manage to reach the Gold III league somehow by playing continuously. I also drained my Energy capture rate by continuously trying with the same splinter but ultimately the outcome was fruitful. I'm quite glad that I was able to reach the next league now itself even though there is still 7 more day available until next season. With this Gold III league now I will be able to get 22 cards from the season rewards and my daily quest reward cards will also be decent. I'm glad that I was able to make it already.
After all that struggle, I claimed the quest reward after I reached the Gold III league. The intention was to get some extra cards from the quest rewards. I'm glad that I got one rare card but the other cards were just normal cards. No big deal but good for upgrading the existing cards as usual.