Sounds tough OP but hang in there & as others have already said, don't give up hope, you're not a bad mother. Teens can be a law onto themselves.
We have 16 year old & exactly as some others have pointed out is a stickler for upholding traditions! I think it's a security thing - they're going through so much change & we're not allowed to change..we're the permanence in their lives..it gives a sense of comfort & as I said security.
Similar to a pp we still do everything the same as we always did..stockings get hung up & Santa leaves the presents in the same place & we give 1 present from us under the tree. Our teen might suggest 1 thing they'd potentially like & we listen carefully to various conversations from months before about things that might be of interest & so they have no clue really what they're getting. That element of surprise is important I think & dh & I love doing it
My teen years were not great as my parents decided I was too old for all that & roped me into sorting a lot out for younger sibling. I can still remember that feeling of flatness that they just couldn't be bothered making an effort for me anymore & lots of years they just gave me money & told me to buy my own presents & give them to them to leave out on Christmas eve for my younger Santa believing sibling
I swore not to do that. And dh never had Santa because his parents never bothered with it. We've had lots of fun over the years creating our own wonderful traditions- perhaps a little too well as dc shows no signs of wanting them to stop!
We do stocking for each other. We do dcs together & I do dh's & he does mine. That's a newish 3 or 4 year tradition we've added as when dc was genuinely of Santa believing age Santa just filled theirs
We get up around 8am & all go down together to see if 'he's been' & we open our stockings together. We light the fire v quickly & sit around it with coffee
Then we open the tree presents in the other room with the Christmas tree lighting.
We make a big brunch with champagne & we eat dinner in the evening with candles & the table set beautifully..
I love our Christmases & I think teen does too. They still escape to their room at various stages but I'm fine with that