How much weight can I lose, by walking 30 days, 8 hours a day?

I'm guessing you're overweight so let's assume you're a 180lb guy hiking with a pack in hilly country.

You're going to be burning over 500 calories an hour on the trail = at least 4000 per day.

During your 16 hours off the trail you'll be burning around 100 calories an hour = 1600 per day.

So your total calorie burn will be around 5000 - 6000 calories per day.

If you restrict your daily intake to 3500 calories a day (I've done this and found it workable) your daily deficit will be around 2000 calories per day.

Now, very roughly you need to burn 3500 calories to lose a lb of body fat. So you could expect to lose a bit over half a lb per day on your trek.

This was exactly my experience a few years ago when I started an alpine trek carrying around 20 lbs of excess fat and a 15 lb pack. After 30 days on the trail, including a couple of rest days, I'd lost around 15 lbs and was a few lbs short of my ideal weight.

Of course the actual figures will depend on your personal body-fat percentage, your metabolism and the height differentials on your walk, but this should give you a starting point.

How to REALLY get motivated to lose weight and live a healthy lifestyle

When we get older, some of us also get weaker thyroid glands. It it very common in older age to get hypothyroidism. When that is the case, the affected person has a problem to lose weight and tends to gain weight. Blood tests including a TSH level (thyroid stimulating hormone) are very accurate in pin-pointing hypothyroidism.

I walked in on my husband having sex with another woman, after years of this stuff. I want to divorce him but he will only agree if I pay his costs. Is this normal? I am in the UK?

It would be at least understandable if you were in a country with no-fault divorce, he didn't want the divorce, and you had a reason to not want to pursue fault divorce. According to this, the UK doesn't have no-fault divorce; and

How to go on if I trashed life and it's too late to fix things

It's never to late to fix things, never. And though 31 looks late to get started from your point of view, it's really not. Think of it this way, you have only been an adult for about 13 years. If you live to 80 you've got 49 more adult