Entitled, controlling, victim, attention seeking behavior

I’m seriously so burned out. I tell my son that no matter what he does, even if he is the maddest mad, or the baddest bad, I will still love him. That is true, but it is getting hard to like him. My son, turned eight a week ago, he is very smart and always has been, for example, when he was 16 months he was determined to learn his letters and sounds, and asked me for toys, videos, etc to teach him and he would sit there as a baby learning with these toys for hours, and he learned it within weeks. When he was 4 and he wanted to learn how to read, he spent 6 hours a day practicing till he could read at a 3rd grade level 3 months later. I say this because learning has come easy and he is prideful and will not receive instruction even though I am homeschooling him. He is intense. He is passionate. He wants what he wants and nothing in this world can stop him. I have always supported his goals, his dreams, and his desires, maybe to a fault because he is now entitled. When he wants something he will not drop the subject, he will not relent until he gets what he wants no matter the consequences to other people. He struggles a lot with envy and will destroy his sisters things when he is jealous. He throws tantrums, I mean intense ones, where he can’t get calm for hours and will not accept consequences in those moments. It feels like when he doesn’t get his way he goes from zero to 100, so fast it’s so explosive, without time to pre teach or anything. It’s scary, and he smashes things and knocks things over on his way to his calm down spot. He shouts disrespectful things for so long, I feel like his emotional punching bag. It’s crazy, because I don't shout often, but if I ever do, his behavior is a 180, he will immediately become remorseful, start cleaning and calm down. On a regular basis he is so controlling of his sister, of me, he requests an agenda of our homeschool day always adding what he desires, he tries really hard, even helping make breakfast, helping his baby brother, tutoring his sister, and completing his school work before I even wake up in the morning to make sure we can complete everything he desires, but if things go off script like a friend canceling, or he struggles a bit in his work there will be an explosion. Then after the explosion, he will feel intense shame, and inadequacy, and will wallow for the rest of the day calling himself stupid, bad, and victimizing himself in an attention seeking way.