Taking creatine does not bar you from doing other things. Being "low energy" is too general a thing, and to approach you probably need to start eliminating factors anyway until you find the issue, by getting better sleep, doing blood tests etc. Taking creatine can be part of this.

Creatine supplementation not having significant effect in X domain in population level does not mean that it will not have effect on YOU if for example you are vegan and don't get enough creatine from diet. If you have low energy, probably you have something that may not show in a population level. Similarly you may be low in B12 and then B12 can help you, but it may not show effects in population level if most of the population is not low in B12 (and your study is not powered enough to catch nuances).

It is not like when you have to choose between two medicines and excluding one can be harmful even if the other is not harmful to take per se. You can supplement creatine and try whatever else at the same time.