I feel mentally sharper when fasting but my gym performance dropped. Is this a phase that passes?

Is it normal to feel colder than usual when fasting? I'm always freezing now.

I feel dizzy when I stand up during my fast. Is this dangerous or normal?

I'm 58 and my metabolism feels like it's completely stopped. Is it too late for fasting to work for me?

I've been fasting for 3 months and feel great but my cholesterol went up. Should I be worried?

I feel great fasting Monday to Friday but always overeat on weekends. How do I stop undoing my progress?