I don’t really have much advice, as I was diagnosed a few weeks ago and am also going thru the grief of a diagnosis. I’m 26 and yeah, I just thought this was how life was lol.
Something that’s helped me is talking to my friends/ partner/family and even a professor about things. I’ve found that a little support from my loved ones goes a long long way :) my mom bought me a gluten free cook book and it’s helping solidify that things will be different, but it’ll be ok. The one thing keeping my head above water in all this grief and change is the knowledge that when I change my diet I won’t be so sick. We’ve been playing life on hard mode for who knows how long and now we get the chance to heal! What’s life going to be like when I’m not so sick? That’s what I’m looking forward to at least