Dear Cat Mum~
Welcome here to the Forum, it is a friendly place and I'm sure you will find everyone helpful and understanding. A good move.
You sound as if you had a tough time in year 5 and also were underweight then. Do you think the weight and the anxiety were linked? For many people they are.
Can you remember what happened that made the anxiety come on then go away?
Now, and I'm guessing you are in your mid to late teens, you have been feeling anxious bad, nauseous and unable to eat -which is itself a worry - again. Yes I can understand it being a scary situation. I'd be very scared too, there is nothing worse than being carried along without any control.
If you do not mind me asking has there been anything to upset or worry you recently?
There are things to do, and they can help a great deal. First though may I ask how you get on with your mum? Is she understanding, someone you can talk to?
If she is I'd suggest setting out exactly how you feel to her -and drawing the comparison with 6 years ago. If your mum is not the right person can you think of anyone else in your family or at school, a teacher or councilor perhaps?
Talking to someone else can give you two things, a person to share your worries with - which can be a real comfort - and at the same time someone to organize for you to have proper medical support.
Anxiety does respond to treatment, and the earlier you start the better. I made the mistake of hanging on for far too long, and that not only made me keep getting worse, but harder to treat too. I'd strongly suggest you take action right now
I may be mistaken, you may already be under medical care. Obviously in that case the treatment is not working and you need to let the doctor know quite quickly. Not eating is harmful (as I'm sure you know)
If you feel you are absolutely stuck with no one to go to then please ring the Kids Help Line (1800 55 1800) who will be familiar with your conditon and be able to really help. Thy are professional but sensitive and caring - you can contact them more than once.
If talking on the phone seem too hard they have web-chat 24/7
https://kidshelpline.com.au/get-help/webchat-counselling/
(The page has the actual chat link at the bottom.) Sometimes they are a bit slow as they are popular.
I am concerned about you and would really like to hear from you again
Croix