Diabetes in the family...!??

So I was talking to my cousin just now (we are both 20 years old) and he was saying that he thinks he might have diabetes; he has felt sick for a few days, constantly urinating, and his toe has been numb the whole time too. Are these symptoms of diabetes or could it be something else? He says he's going to the doctor tomorrow to see but I wanted to find out who here has or knows someone who has diabetes. How hard is it to live with? He's really down about the whole thing and feels like his whole life will be turned upside down if it's true. I'm trying to be supportive because we're really close, he's one of the few people who think like I do and loves Mopars as much as me lol.