Maybe speak to someone at BEAT - they are an eating disorders charity based I think, in Norwich. They probably have advice and support groups on offer. You recognise your problem which is a start. ........ and breath. Relaxation therapy can help, concentrating on firstly the toes: stretch them, count to 5, relax. Do this through all the muscle groups up the body.
Head - staring straight ahead. Blink the eyes slowly; open, close. Head forwards to the chest, wait, lift. Turn head gentle to the left, wait. Return to central. Same to the right, wait. Return to central. All this takes practice but can help as it focuses. Singing makes a person breath correctly.
What support do you have with caring for your daughter? Is she in school? Does she have friends if you need a break in order to try medication etc.?