Fiancé Anxiety Problems

My fiancé of almost 4 years recently started having his anxiety attacks come back to him. He went to the doctor to get back on his same medication he was on like 6 years ago. He says, maybe it’s starting to help a little but he still feels like sh*t all day, everyday. He has been at his “new” job for only like 2 or 3 months and he has called in 6 days total all because of his anxiety starting back up. He says, everyone at his job knows what’s going on with him. But for me, I have no clue about anxiety. I don’t know anything about that stuff. I don’t have any problems like that. So I don’t know what he’s going through or what he’s feeling. Only except what he tells me and how he looks like. I feel extremely bad for him because he’s missing out on all this work and I don’t want him falling behind on his bills. I just don’t know what to say to him about all all of that. I don’t know what the right or wrong answer is. I don’t want to say something mean to him. He says, his anxiety causes him to be so nauseous he can’t eat, he doesn’t sleep at all except a few hours, his whole body feels so hot but he’s feeling cold, dizzy spells, migraines, and really bad heartburn.

I don’t know how to help him.

I don’t know what to say to him.

Any advice will be helpful.