is it possible to have celiac disease and diabetes?!

Yes!
I have both.
A pain but manageable.
They often go together.
Just about any store has a good gluten free range these days.
If you cook, just substitute gf flour for normal flour and the recipies usually work out.
The cakes and biscuits you can buy are good now. Bread is horrible though.
fresh plain meat, and veges are always an option
Good luck. Message me if you want

Diab
Celiac
mum

Yes. One disease won't prevent the other. As to diet, if you do have both, please get a diet from a registered dietitian. That would be really complicated, and the wrong diet could have serious consequences.