That all sounds normal.... Nicotine is a really strong and addictive drug and the withdrawal symptoms can be really hard.
The good news however, is that 90% of the nicotine will have left your body after 3 days so the physical withdrawal should be much easier from then. That was the danger point for me though because I started to think I could just have "1 or 2" and stop again. Breaking the actual habit is by far the most difficult thing
Every time you get a craving, do something else until it passes. Glass of water, cleaning teeth, eating drumstick lollipops all helped me.
I stopped about 5 months ago. It is really difficult but worth it.
My parents have also just stopped after 30+ years of smoking 40 a day. They did it via a smoking cessation clinic and had nicotine inhalators. They've been smoke free for 6 months now.
You know all the reasons why you shouldn't do it but you just have to make the decision that you will NEVER be a smoker again. Be strong and good luck