i hate my ring and can't let go

Some context: I am a minimalist. I dont own many things and I choose them carefully. I love decluttering, making space, keeping things in order and owning only meaningful stuff.
I hate receiving gifts, I am very stressed when I am about to get one. I feel ungrateful when I am supposed to keep something I dont need, something that's not functional, not my aesthethic and I usually hide it so it does not bother me.My fiancee understands it and never buys me anything unless we choose it together.I was 100% sure it would be the same with engagement ring.Was I wrong.
He took his cousin shopping and he chose something they both liked. Non exchangable, non refundable.
I told him he doesnt need a ring to propose, I didnt think I needed to specify I want to choose it myself. I was certain it was obvious. I thought that even if he wanted to have a ring to propose we would exchange it later if I didnt like it.
The ring is nice but not something I wanted at all. He didnt asked about what rings I like, just some vague questions about jewelery, probably not to sound too obvious. I thought I could let it go and I wore the ring everyday out of loyalty but the resentment started to grow.
I once mentioned I would like to modify it. My fiancee said I could but he would feel hurt as he tried so hard and likes the ring the way it is.
Engaging a cousin made it worse. They grew up together and are close but me and her are not, she doesnt really know my style and preferences.
They tried rings on her finger. We're both thin but "her hands are so tiny" so while her size is 52, they chose 62 for me. We had to decrease it to 54 and its still bit loose. I am not sure what her insight on the size was, but I find it upsetting that he had the other woman hand as reference and chose 10 sizes bigger ring.
She also made comments at different occasions that reminds me she was there instead of me. "He made the good decision, I dont like round stones, they're too popular" (I like them). "It was important to me that the ring has accent stones" (I dislike them). I feel like she wants to show that they tried to choose something pretty for me but maybe subconsiously she wants to show she's important to him as her input mattered.I never voiced my opinion in response to these comments, because what could I say?
The comments were what made me despise the ring completely. I feel excluded from very important decision. I feel somebodys opinion and taste is more important than mine (when nobody else should be even involved). I felt a relief when I found out the citrines scratch easily and are not suitable for everyday wear. I stopped wearing the ring.
What do I do now?
I am devastated that I dont have my dream ring, the one I planned on wearing everyday for the rest of my life. Or the ring that doesnt cause such negatives emotions when I look at it.
Though the current ring seems "affordable" (0.2 ct citrine and thin band), I am afraid he paid a lot for it, as he chose an expensive brand (I could not care less for the brand). We both earn good money so we could afford even a new diamond ring (I am OK with diamond imitation as well) but I would feel like I am wasting money he already paid.And I am afraid he would be as hurt looking at the new ring as I am looking at the current one.
Modifying ring seems like sad compromise (it still would not be my dream ring and he would be unhappy I changed it).
He doesnt know how this situation tortures me. I am anxious about telling him this as I dont want to hurt him and our relationship. I know his ego will be hurt and he'll feel bad for disapointing me. Maybe think I am ungrateful. Him not wanting any changes doesnt look promising as well.
How do I approch it?