I'm sorry you've been diagnosed with T1, it's a lifelong illness (probably, though there is hope for a cure in your lifetime, if not mine.)
I've been T1 since the age of 8, for 50 years, so I don't really remember much about life before diabetes. But it certainly hasn't stopped me enjoying my life, and my health is still good, despite many years of mediocre to poor control before glucometers became available. No one's ever told me that I would get coeliacs, though I do understand it is a bit more likely for T1s. (It's still very unlikely, just a bit more likely than for a non T1).
Though it's not a disease I'd wish on anyone, it is one where the patient can have much more control than the doctor. In the long run, as you learn about how carbs, insulin, exercise, illness, stress and everything else interact with your body, you'll learn how to optimise your dosing and lifestyle decisions, and there are few paths in life that are closed to you. Modern treatment for T1s is improving in leaps and bounds, and I really don't see why you have to inevitably get a whole load of other illnesses as a result.
Can I ask which country you are in, as options for medical help and food choices do vary by country, though the basic illness may be the same? Remember, whatever the issue, whatever the time of day, they'll always be someone on these forums to listen and (hopefully) offer help and advice. Diabetes affects everyone differently, but there's a good chance that whatever issue you face has been faced before by others on here. There's a very steep learning curve for managing this, which can seem overwhelming when you start out, remember you don't have to learn it quickly, it's the long term (years and decades) that is important.
Good luck, keep safe, and try to remember that things will get easier in the future.