Hi L.,
My son was this stubborn as well. Nothing seemed to work. It started to affect not only him, but the rest of the family as well. Plus, not only was it destructive, but by 3 years old, he started to not care about consequences, and it became dangerous.
I am stubborn as well, and didn't want to think my child could have anything wrong with him. Now, I'm not saying your son has it, but once I finally broke down and realized something was drastically wrong, we found out he has an extreme case of ADHD. I thought he was being just your typical 3-4 year old kid not wanting to listen. He was a boy, and I thought some boys just acted like that.
Once he was diagnosed, we went through a couple different medications before we found Adderall worked the best. He is a totally changed boy. He is 5 now and starting Kindergarten this fall. In a matter of a year-year and a half, he has turned into one of the most well mannered, smartest kids in his class at daycare/preschool. He is easier to manage and above all, he is no longer a danger to himself, or his little brother.
He still has his occasional outbursts, but they are very far between, and not multiple times a day like before. It also helped that we set up a 'day chart'.
Our Day Chart consists of the things we normally do throughout the day.
Morning: Wake up, go potty, get dressed, eat breakfast, brush our teeth, leave for school.
Afternoon: Get home, free play, dinner, quiet time/bed time, bed.
We separated everything out in quarter hours, 15, 30, 45, and 00. He may not be able to tell him exactly, but we put a big standard clock in his room and he knows when the big hand is on the 6 (for 6:30) that it is time to wake up. When the big hand is on the 9 (for 6:45) it is time to get out of bed, go potty, and get dressed. When on the 12 (for 7:00) it is time to eat breakfast. When done we brush our teeth, and relax is we have time left over. When the hand is on the 6 again (for 7:30) it is time to leave for school.
This has helped us greatly, because I think it gives him a feeling that HE controls the time.
Either way good luck. I know how frustrating it can be. anything you do will take extra effort on your part, but the reward will be so worth it. I love being able to sit with my son and read a book rather than yelling at him the whole time to not turn/rip the pages.