I really agree with @DeftGoldHedgehog bout this 'I know not everyone has the same hormonal issues as me but it is quite common at 40 to be in a phase when your body is out of kilter hormonally and under a lot of stress.'
I've spent my adult life doing ultra long distance sports, suddenly in my 40s they do not agree with me anymore - I need to lift heavy weights. I think it is completely underestimated how important it is to stop doing things which cause your body to feel stressed in this way. Ignore it at your peril.
You are not going to be healthier and happier by fatiguing your body in the way you mentioned.
When you add in extra exercise load, you need to support your body with extra food and rest. No matter what they say about torching calories HIIT is not good for weight loss because you cannot do it for a long time (like walking or cycling). As you have found, you will need to support your body with extra nutrients and rest if you want to make 4 x weekly HIIT work. HIIT is great for improving fitness, but not really for weight loss. People training for marathons often find the same - you need to eat more to have the fuel to support training for it, so they don't lose weight, they often gain it. If they don't train in the right way they are exhausted, irritable, emotional and miserable. But training for a marathon can also be joyful if you don't overstress your body.
The best exercise for weight loss is moderate intensity done for a long duration - a long fast walk twice a day would do it. If you've already found something you enjoy doing for exercise then go back to that - m add in some walking or just extra movement in the day and give it a bit more time, our bodies often need much longer to adapt than we realise. Fitness will make you healthy and enable you to be able to lose weight in a healthy way in the long term, you'll have more energy to be able to do more.
Go back to the thing you enjoyed and take a look at your overall lifestyle, add in fast walking which makes you slightly out of breath. You'll feel so much better overall and you'll be much more able to deal with the stone you want to lose.
Don't keep fatiguing your body like that, it'll start throwing up all kinds of problems at you. An injury will stop you doing any exercise at all. You can't treat your body the same way in your 40s+ the same way you could in your 20s.Take it from someone who used to run competitive ultra-marathons - you have to listen to what your body needs. Exercise is not meant to be a punishment for being a little overweight, use it the right way and it can bring so much energy, vitality and happiness to your life for years to come.