I am very much a newbie (and not a man, so I don't know if that makes a difference, LOL), but I shall try to help. How long have you been eating paleo?
I had a VERY hard time going low-carb when I first started - shakes, fatigue, the works. (I'm primal, by the way - I even eat dairy, in limited amounts.) I found that I did better if I ate when I was hungry, and whatever sounded good - excluding grains and other taboo foods, of course! If I wanted bacon, I ate bacon. If I wanted veggies, I ate veggies. If I wanted a little bowl of Greek yogurt with berries in it, I ate that. For me, the first two weeks was about training my body to eat a certain way, and to get used to burning an alternative fuel source. After a disasterous first few days, I upped my carbs to just under 100g, and upped my fats and protein along with it. The first two weeks, I was eating about 1800-2100 calories per day, with about 60% of those coming from fat, and 15-20% from carbs. As time went by, I found that I could start IF'ing on a limited basis and still feel okay. Now my fat ratio is about the same, but I'm only eating between 1200-1600 calories per day, and my carbs are under 50 most days. My energy level is great, though I do up my carbs a bit on workout days - if I'm too low, I feel fatigued and get very weak about halfway through the workout. I feel like things have really "clicked" the last week or so - but it took several weeks to get here.
Everybody's body is different, and therefore everybody's experience is also different; but I hope you find out a system that works for you and you get to feeling good. I am amazed at the difference in how I feel since I started following PB - even though I didn't start losing weight until just recently, the benefit in my mental and physical energy was well worth the lifestyle change! Good luck! Hopefully some of the paleo/primal gurus will chime in and have some helpful suggestions.