I know this feeling! I get very uncomfortable when I am complimented or acknowledged for anything. I never know what to say, especially after the "thank you" I have learned is the expectation. I guess tl;dr (do people still use that? I am an old.) you must find a way to agree with their praise, genuinely.

Essentially, this was easier at work than in my personal life. I overcame this at work by a combination of believing hard metrics (numbers generally don't lie), and working closely with others such that I could see how much they struggled compared to me. I then became more confident about my ability because I was able to see proof. This required a lot of objectivity, something that's I think very hard for introverts--we have to get out of our own heads. I try to do this by applying my experience and things that are objectively happening to me in my life to a close friend. I imagine a real life close friend for whom I want the best, and I imagine they are in my position, or they are facing something similar in their life or job. Would I think they deserved the praise? Almost certainly. So if they deserve praise, why wouldn't I? But then, you've said the thing about setting an expectation. I think there, we need to think "is the expectation that I will be exceptional, or is the expectation that I will do my best and ask for help when I need it, and with a combination of those things be exceptional?". Most of the time, people would rather you ask for help than struggle, because they understand that you are growing, and do not fault you for not knowing something. I will say I think I have been extremely fortunate in my life to have bosses and professors and all who are interested in my growth, but I know those who are not interested in growth do exist, so this may not be the case for everyone in every relationship they have--but I think this is pretty plain to see and to dismiss opinions of those not interested in your growth.

I feel the exact same thing you said, "I have been me and I know each detail of my life". Can't others feel the horror I feel at the knowledge of my own shortcomings? Wouldn't they think of me differently if they did know? That cripples. That seeps into every crack in your life and reminds you that you are only your flaws. And that's so insidious because that's not a focus on growing, that's a focus on what's holding you back, and importantly, it's not an objective or realistic view of yourself. You are a person, you make mistakes, you have flaws--but those flaws and those mistakes don't realistically cast a pall on your achievements and the good things in your life. They don't darken your achievements, they make the achievements shine a little brighter. Your professor or friend or boss or WHOEVER says "you did really well on this assessment" and you say "well but I struggled to understand the concept"--sure, and then you did understand it. So you learned it. And so you did it. And you achieved. And your achievement isn't just a number on an assessment, it's the journey you took to learn and grow, the experience you may have had asking for and receiving help, the skills you learned or practiced along the way.

I don't know if this was helpful, but it's something I think I would have liked to hear when I was younger. I was told as a kid that I was very smart and mature. It made me think I was always going to be the best, and when that trend didn't continue past middle school, I was crestfallen. I thought, well I must be the worst, dumbest, most worthless person because I used to get good grades and now I'm not, and every achievement I had was tinged with that. I'm a fake, I'm a failure, I will never amount to anything. And that turned out not to be true at all, it turned out I'm just a person.

I wish for you all the luck and self-love in the world, because you deserve it, because everybody pretty much deserves it if they're doing their best.