Low Energy on Keto + Supplements

Greetings all,

Hope you are all doing well and staying safe and healthy. I am writing to get some advice re: my energy levels. When I started strict Keto 1/1/20, after a couple weeks of being on the diet, I felt my energy levels sky rocket. I felt my brain fog lift and overall felt I had more "clean" energy than ever before. In fact, I didn't even feel like I needed my morning cup of coffee. However, being almost a full 4 months into a strict keto diet, I have noticed my energy levels drop dramatically. In fact, I feel more exhausted and lethargic than ever before. I am getting plenty of sleep 8+ hours and am eating all my same keto foods and have not wavered. The frustrating thing is now I wake up and coffee has no effect on me. In other words, I can drink as much of it as possible and it won't do a thing for me. Almost feels like my adrenals are tapped out. It's quite unfortunate because I have never looked better. I am more fit at 38 than I have ever been in my life...and I barely work out. In that capacity, the diet is amazing! I just wish my energy levels were higher. Does anyone have any thoughts or insight on this? Should I start adding in more Paleo foods and do a hybrid Keto/Paleo diet? Are there any supplements out there that are natural "uppers" that increase energy and cognitive function better than caffeine? Before going on this diet, i used to drink sugar free energy sodas like they were going out of style. I have not had one since I started this diet and unfortunately am feeling drawn back to them just so I can get some work done and not feel wiped out all the time. I thought about Mate, but I think that is less caffeine than coffee. I don't know...any suggestions would be greatly appreciated. I'd hate to quit this diet because of this chronic fatigue, but if I don't figure something out, I might have to. I look forward to your thoughts :) Many thanks for your time and help!