Honestly, you print out what you wrote in your post, bring it to the therapist, and say, "Help me fix this".
In order to "fix" who you are today, you MUST first understand WHY and HOW you got to be the person you are. And you are right, it's damn near impossible to know where to start when everything you can remember is fucked up.
I'll use myself as an example. Growing up, my mother was a narcissist as well as religiously extreme. My brother was a sadist and I was his favorite playtoy to torture. I was fat, I was Jewish, I was a D&D nerd, I had some autistic tendencies, and I was in the gifted program. In other words, I was a bully's wet-dream, and got bullied, teased, humiliated and beaten up daily. I was sexually abused as a child, repeatedly. My father was never around and then died when I was young. A therapist once asked me to write down every childhood trauma I could remember, and it ended being 5 pages long, double-sided. So... like you, when it came time to "start from the beginning", I barely knew where to begin.
If it were me, I would start with the entitlement. Figure out where that comes from. Why does it exist? What did it do for you at the time, and what does it do for you now? Entitlement is a natural precursor to anger, rage, lack of empathy and often results in behavior and decisions that are harm yourself and others.
If your background is similar to mine in any way, I would also consider looking into your shame. Shame is a huge issue for most WS's, and entitlement is a great way to mask shame. My therapist and I did some EMDR and some hypnotherapy, and had me go back to my earliest days and remember my very first experiences with shame. Doing so really helped me, A LOT, because I realized that the much of the shame I carried was not mine to bear in the first place. For example, let's say that your Dad called you "stupid" and "lazy" as a kid. So you grow up thinking that you ARE lazy and stupid, and that's shameful, and you don't want to feel shameful about it, so you get pissed instead. Then what happens? One day, your wife says, "Hey, did you pick up a loaf of bread like I asked you to?" and if you didn't, you suddenly trigger back to feeling stupid and lazy (shame) which makes you angry in response, and then you end up blaming your spouse for your anger (misdirected anger/blame) and end up telling your spouse "to go fuck themselves" without ever really understanding why forgetting about a loaf of bread turned you into the Hulk.
The other half of the equation, once you know WHY you feel the way you do, is the CHANGE THE STORY in your brain. So to follow the story we've setup, you would look back at how your Dad treated you and say to yourself, "Wait a minute. I WASN'T stupid, or lazy! I was a little kid and it was my Dad's job to protect me, to help me grow, to teach me to love myself... It wasn't fair of him to take out his rage and his anger on ME, A LITTLE KID." Knowing that, you can then take actions (with your therapists help) to rewrite those stories in your head, so that you stop triggering over false memories. Instead, you start to remember that you were a Smart, happy, loving and good kid who would have turned out just fine if not the trauma inflicted upon you, trauma that WAS NOT YOUR FAULT AND THAT YOU DIDN'T DESERVE. When you stop being angry at yourself and your trauma, you can stop being angry at the world. Understand?
Honestly, the hardest step is in getting to the therapist in the first place. From there, just be open minded, try to understand rather than trigger, try to be curious rather than angry, and have fight the desire to just continue to be the same way, and instead, insist on being better. Being happier. Being someone you love and trust and respect. I can tell you from experience, once you DO get through it, it feels like an iron chain has been removed from you. You can breathe. You can smile. You can feel good about yourself again. Hard to believe, I know, but I swear it's true.
I wish you luck. Please keep coming back, almost every WS here shares a lot of the things you mentioned, so you are among safe friends here in that regard.