You're probably eating low carb, and unless you have some specific medical issues there's little reason to, especially if you feel tired. Correct me if I'm wrong. But most people will tell you to "eat more fat" which, if you're pretty low carb, is not the solution. Instead, eat more sweet potatoes, bananas, etc.

The other likely problem is that you're just not eating enough calories, but if you're trying to lose a lot of weight that might be something you have to power through, or else just try adding 1 sweet potato or something like that to what you're eating per day without going crazy adding 1000 calories.

If you are eating a low fat paleo, try adding some nice fatty fat fat. Coconut oil, butter, avocado, etc. You don't need to go crazy, just add some fat, maybe fattier meat if you're eating skinless chicken breasts.

If you are eating a low carb paleo, try adding some carbs. Fruit, sweet potato, avocado (again!), maybe even some white rice. Again, just enough so you feel better.

Also make sure that you are not nutrient deficient. Check meals in fitday to see if there is anything amiss. Find food that helps (kale, liver, shellfish, bone broth).

Other things to check: sleep, vitamin D/sunshine, stress levels, working out too much.

It's certainly not an uncommon story, and often goes with getting stuck on one definition of 'strict paleo'. If you are eating the same things in regular meal plans then this is likely to be a problem unless you somehow manage to get your plan exactly right. Your needs change. Have you been losing weight? Are you in the northern hemisphere? You can affect a lot of things by playing with your diet but that doesn't mean it's necessarily what you need to do. The 'paleo' thing to do right now may be to curl up and sleep for 12-14 hours, conserving every last bit of bodyfat until Spring.

There's a reason why you're feeling tired. If you're still overriding your instincts after 3 months then it may be that you need to allow yourself to eat more - a day or two of feasting on paleo foods will easily test your appetite without too much risk. If you're not hungry then just adding extra calories to force your body awake may not be the healthiest thing. Mixing things up, eating more fat or carbs (or protein) depending on what you've been eating so far will probably produce a change of some sort, as would playing with IF. The main thing though is to learn what your body needs, and right now my best guess is that it wants to sleep in the dark for about a week.