Exhausted

The coldness and exhaustion are key symptoms of an underactive thyroid. You say you've been checked out medically, but have you had a blood workup done? I'd ask your doctor to do a thyroid blood check and rule that out as well.

It could be a number of things, hard to say without seeing your diary or knowing exactly how you exercise (and not excluding medical, even though you've been checked).

When you say low-carb, how low-carb are we talking? 100g/day? <30g? How long have you been on it? What are your macros, how many calories are you eating?

If you've just started a low-carb routine after a high-carb lifestyle, it's not unusual to feel drained for a little while.

Did feeling exhausted coincide with going on a low carb diet?
How many calories a day are you eating? As your diary is locked you aren't giving many clues to go on!!

Have you checked if you're Vit D deficient? I found that that was one of my issues.

Also if you are doing low carb, I think it's pretty normal that you feel low for days 3-7. I had flu-like sypmtoms last week and felt horrible but I'm feeling awesome now

Could be your body adjusting to the change.

Since your diary is closed, it's hard to tell if you are eating sufficient nutrition. Since you had a heart attack, you want to be sure to check with your doctor before making major changes but take a look at the information at Harvard's Nutrition Source http://www.hsph.harvard.edu/nutritionsource/ and see how your doctor feels about the "Healthy Eating Plate" for a nutritious diet. Also, make sure you are getting enough sleep.

I go to my neighborhood herb store, the people have been in the biz for as long as I can remember, so they are very knowledgeable. If you know of a place like this where you live, go seek their advice. Where I go they can look in you eyes and tell you what systems in your body are weak, and suggest what you could be taking, (herbs) and eating to help support these systems. I don't use this instead of a doctor, but along with. This approach has done wonders for me!

I take supplements to help support my thyroid, to help with inflammation, fluid retention, and progesterone, which has helped me with hormonal imbalance, after a hysterectomy.

I have also drastically changed my diet, I exercise just about every day, and I drink a ton of water.

I am like a new person, the woman that was in so much pain, tired all the time, depressed and kinda grumpy. She doesn't live here anymore!

I hope you can find a place that deals in this natural approach to helping you feel your best, it really works, at least I am a believer!

Ok, so I checked back a week or so in your diary, you are eating between 950-1500 calories tops a day. Seem to be averaging about 1200. I am not sure of your weight/height but you said you are still in the overweight category, so I'm going to assume that you weigh more than I do.

For me (and I weigh 65kg) that intake level would be too low. If I eat lower for a few days, I feel exhausted and lethargic and emotional, all over the place and think about food all the time. For me, that tells me I need to eat more, and sometimes I'll have to throw in a sweet potato or something with my lunch and some museli or some type of oats with brekkie for added energy, especially on a training day. I only aim for 100g carbs a day (some would say this is low) but I am gluten intolerant, so do not eat a lot of starchy type stuff, but I do eat a lot of green veggies and berries.

You may possibly need to eat more.

Low carb is fine if that is what you choose to do, but you still need energy from food, so get some extra protein and fats into your day.

Work out your TDEE and take a cut of 20%. You will still be in a deficit but will have a lot more energy and will be able to sustain your weight loss.

Has the doctor checked your iron levels? This is exactly how I feel when my iron is low.