Hi JSP,
Weight loss or gain is common with anxiety or depression, so what you're experiencing isn't too unusual, but if you're having concerns about your weight, please see a GP or therapist. If food makes you feel nauseous, it may have a physiological cause, rather than a psychological cause.
If it is psychological, it may be a conditioning effect where you've associated food with shame, which is possible if your anxiety was partly body-image based. That will subside with time and good decisions.
When I was in my late teens I had anxiety really bad, and I think I lost about 15kgs in around 2 or 3 months. At the time I was really proud of it because a lot of my anxiety was image-based, but looking back on it now I realise that I was a terribly unhealthy thing to put myself through.
Weight management is something that people with anxiety often do to ease their anxiety. For example, if you're anxious about your body, except for when you see that the scale is a bit lower, that may encourage you to eat less so that that you keep getting that brief painkiller/reward effect when you see the scales.
However, there are some side effects - one big one being that our mental wellbeing is tied into our physical wellbeing, and if our body is stressed, our mind suffers too. It's important to get adequate nutrition to help your brain rest and heal. My anxiety started to ease when I stopped trying to lose weight and started eating properly again.
Nowadays if I feel stressed, I go the opposite way and I tend to eat my feelings, but mostly my anxiety these days is work-related instead of body-image related, and this too is a reinforcer of bad eating habits (food provides dopamine which eases anxiety). So yes, at least for me, anxiety has a strong relationship with what I put (or don't put) in my mouth.
Perhaps you could speak to a councillor at Beyond Blue to find healthy ways to ease your anxiety?
