Make sure you are getting enough electrolytes: potassium, magnesium, and sodium. That will help with the sluggishness, and should be something you keep up the whole time you're doing keto. As for the waves of hunger: just eat a proper meal or a high-fat snack when you're hungry. Don't deprive yourself, because there really is no need. Just make sure you're getting a good amount of fat, the right amount of protein, no more than 20 carbs, and stay on top of your electrolytes. That alone should start to change your body composition. Once you add in weights, that will change the whole story even more.

Since you're still not sure about what you can eat, and the details, please check out the Keto FAQ, which should have all the answers you need, and you wont need to subject yourself to potentially snarky negative comments. Those FAQ are applicable to anyone, even me at my petite 88lbs.

I am very skinny, and find keto to have been beneficial in a million ways, and I don't feel it is remotely dangerous. It may ease a lot of your problems, and with more mental clarity you'll likely refine your goals/questions. Good luck.