How to stop feeling embarrassed during sex ? It ruins my relationship

My boyfriend (24M) and I (22F ) have been together for 2 years, and we have been having sex for a year and a half. He loves it, he used to get hard every time we kissed at first, then weeks after our first time nothing anymore. I believe he is the one i will marry so that’s why i gave my 🍒 to him.

It's like he doesn't want me anymore and yet he tells me he still loves me, only it's complicated for him to appreciate when I seem too "tense" he told me, he also doesn’t like the feeling of begging for sex. It's true, it's not that I don't like making love to him but I feel embarrassed and yet I love what we do, I'm just too ashamed to make noise and show any emotion, I hate dirty talk and I only like the missionary position because my knees can't stand too much movement, not to mention the fact that it's very embarrassing to be seen from this point of view and the same goes for doggy style, I'm even ashamed when he wants to try to please me by giving me cunnilingus because despite my impeccable hygiene it makes me anxious to smell bad.

I am so jealous of the couples of friends we hang out with because i can see how much he kind of find what they do normal in a relationship, like some are so freaky that they fuck in the next room when we have parties, have pretty naughty private photos, have revealing hickeys, have hot anecdotes that they manage to reveal during drinking games, I wonder how can they live that way, only the very idea of people knowing that I do that would’ve bother me. I pay a lot of attention to modesty, and I find what they do inappropriate, sometimes I wonder if they just don't like each other for their bodies? And I don't want that, i don’t want to be seen like a sl**t.

Only, for him I want to make an effort but in private, what do you advise me and what kind of position should we try ? ( I'm not a big fan of n*des).

I’m so scared of him leaving me because of how i think, i can see that he loves me and try to cool down things but it bothers me so much to be this way when i love making love with him, it makes me sad that he thinks i don’t want him.