afsana, they don't give us a manual about parenting - and they don't give our kids a manual on how they should behave - the only point of reference we have is our own parents!
Parenting is easy when you have easy going compliant children, but if you have wilful children, you have to change what you do.
If you keep doing what you're doing, you will keep getting the same result.
It takes some insight on your part and some hard work and it wont feel natural, but it is worth looking at what you are doing now and modifying your behaviour and parenting style while he is young. It leads to a much happier household in the long term, but it will take a couple of months to get things sorted - and you have to persevere.
I particularly like the book I reference because it talks about how we get into a "dance" with our kids, a typical pattern of requests and defiance that escalates and escalates until the adult is furious and the child is depressed.
He teaches you how to shortcut the dance and offer choice/consequence alternatives.
In our situation, we had an out of control 8yo DD who was so bad we seriously considered fostering her :( our lives were miserable. Her life was miserable. Our other children were scared to death of her. She was violent and out of control. :( It was an awful, awful time for us.
It took a big leap of faith to actually confront my own inadequacies as a parent and to understand that everything I knew about parenting was wrong.
We changed everything - it was not easy and also brought up some spectres from my own past (but in the long term, that was a good thing as it helped me understand the dysfunction in my own family). My DH also had to look at his approach, which was very different from my own but dysfunctional in his own way (boarding school from very young, over-compensating indulgent parents). We had to learn to back eachother up & follow the same rules.
Now 7-8 years on, my DD is delightful and smart and secure. SHe is still willful, but we have learned how to handle her. ANd we parent the other two kids more consistently as a result.
There are many different parenting classes - parenting puzzle is another one that is popular, but they all follow similar guidelines - positive parenting with firm boundaries and consequences - preferably immediate - for poor behaviour.
As an example, my ds2 has started scratching his brothers face. He is 9. So he has been told that if this happens again, there will be consequences - he will loose all screen time for a week (previously it was for 24 hours, but he has done it again). If he was 3, then it would be a lesser time - like no TV for the morning or early bedtime or in room for 5 minutes. And I will follow through if he does it again. Rigidly.
Give one warning. spell out the consequence. One punishment decided before the fact, so you do not overreact in anger when they push the boundary.
But also, lots of praise when they do the right thing. Simple rewards - like - if you walk nicely and dont run off, we will stay in the park for an extra 10 minutes and I will push you very high on the swing.
Sticker charts are very good at his age. 5 stickers in the day mean an ice pop or similar. DOnt take stickers off for bad behaviour. Just reference good behaviour. as in "Oh dear, only 3 stickers today. Maybe tomorrow you can get 5 then you can have an ice lolly"
Dont beat yourself up either, as you can only parent the best way you know how. Learning better ways is up to you!