Splinterlands - My Death Splinter is draining my rating

A day before yesterday I was really very happy to progress good in the game. My progress was very good as I was able to continuously win some games easily to complete daily quests. But I don't know what is happening with my deck yesterday and today. I was thinking that only my Life Splinter is at a low level but today I'm able to realize that my Death Splinter is also in danger Zone. If you see the below image, you will be able to understand what I'm talking about.

I really feel bad to reduce my rating so much and drain my Energy capture rate. Looks like I'm not good in defining my cards with the Death Splinter. When it comes to other splinters, if you have good cards, you have a great advantage to win games easily. But when it comes to Death Splinter, you really need a good strategy in placing the right cards in the right place. Even if you are strong with the cards, you have equal opportunity to lose the game.

I usually skip Life Splinter because I don't have enough cards with me to handle the opponent in high ratings. But after I refresh the quest and end up with Death Splinter, then it again becomes another headache. That is what happened to me today. Something I understand from this is that I cannot keep my Life Splinter like this for a long time. I have to somehow upgrade my Life Splinter to match with the opponents. I don't think an upgraded Life Splinter deck can give headache like Death Splinter.