I feel worse on fasting days than non-fasting days. Is that normal at the beginning?

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?

Does anyone else get really bad headaches in the first few days of fasting? How long did it last for you?

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?