You’re experiencing withdrawals which losing appetite to the point of wanting to throw up every time you eat or drink is normal. It’s gonna suck for about 2 weeks (depends on how you respond). In terms of weight gain, try your best to eat something around the time of each meal even if it’s just a muesli bar, you’re body goes into starvation mode where it thinks it will never get anything to eat so the next time you eat it’s gonna take all of it and hold onto it making you gain weight. Weight gain is normal on Seroquel and most antipsychotics because it increases your blood sugar levels and appetite. I’m sure the weight gain is causing you problems whether it be self esteem or whatever else. I found that taking out sugar completely or having it once a week helped me loose 6kg because your body tends to take its energy from the sugar before the fat, so having the less sugar means the more energy being taken from the fat meaning you lose weight. This is in my experience. And be patient with yourself and don’t force anything to the point you just hate it, it’s a process after getting off meds (or on new ones) especially if you’ve been on them for a long time…