low energy - have you tried tracking what you're eating? Maybe you're not eating enough, or not enough fat/protein or something... maybe try tracking your food for a week and see if it gives you any insight.
Low-carb flu doesn't tend to last more than 3 weeks in general, but a few people here have mentioned that theirs took 6 weeks or more to work out. Everyone's body is different.
Also look into vitamin deficiency of some sort for low energy - I know low B vitamins can cause sluggishness, for example. I'm not a vitamin expert by any means though, so you'll have to google around for other deficiencies that might result in your sluggish feeling.
Constant heartburn shouldn't be normal for anyone! And meat doesn't cause it... nor does fat. (Unless you just eat too much, period.) Have you cut out caffeine ? Caffeine can contribute to heartburn - so can acidic foods like tomatoes and citrus. Also, there are external physical factors like if your clothes are too tight or if you are lying down ... you can get heartburn that way. (Or if you have a fetus/uterus pushing on your stomach causing food to "back up")
Definitely look more into the cause of YOUR heartburn... this is NOT a normal thing and you shouldn't ignore it.
I also have more heightened sense of smell from being primal - especially for smelling processed-ness. haha. I can be near someone snacking on potato chips and actually smell the oil itself. It's gross. Today I ate some goldfish crackers out of desperation (was nauseated at work and wanted a quick fix - something to absorb the stuff in my tummy) and they tasted like rancid oil to me. so nasty. I think that's a normal thing that many of us have experienced.