To think is because of something I'm doing.

[Justturned50]

One DS 17 is taking Beta Blockers having lost loads of weight during and after GCSEs. Poor appetite and frequent vomiting after his evening meal ad a result of panic attacks. I'm so worried about how thin he is and how his mood is lower much of the time.
Second DS 13 has just begun refusing to go to school. The more I read the more I'm pretty sure he's not faking and pretty much a 100% attendance every term until this one. He's usually a chatty vibrant little thing who has become so sad and distressed when he finds he can't face school.
DH is doing his best but worries so much he ends up with a migraine.

Where am going wrong?

Have you spoken to their school? Do they have any concerns (bullying etc)?

Are they at the same school? Maybe something going on there?

Yes same school. DS13 was bullied and the school has dealt with it well and have provided counselling which helped. Pastoral support are also helping. Haven't spoken about DS17 as he's pretty well adjused at school. Happy to be there and enjoying being in 6th form.
Just worried that I'm not supporting them properly.

I don't know how your relationship is with your DC so I can't comment much but if you have a generally good relationship with them, I think the most important thing is to make sure they know they can always talk to you about anything. I know that's very general advice, but it's an important stepping stone.
Personally I would take DS17 to GP (of course due to his age he'd have to agree, maybe you can encourage him to see GP himself?). It all depends on how long he's been this way. I can only imagine how worrying this must be for you . And for DS13 maybe try to see if the bullying has started again? Or maybe something has brought back the memories of the experience?

I wonder if your older son has an eatinng dosorder as well as anxiety. It's a very difficult time for teens and an eating disorder could be an attempt to take back control.
Sounds very hard for you all.