Lildubs01 I suffered with eating disorders for years in my late teens and early twenties - well done you for recognising that you have a problem. Hopefully the Dr will be able to give you some help - as other posters have said this could be linked to PND or could be separate, but either way make sure they take you seriously and enable you to get some help.
The greatest help for me was going to a hypnotherapist who helped me work through all the issues that lead to my eating problems (eating to fill an emotional hole vs starving myself to give myself a feeling of control over something in my life) and that helped me to get some perspective on why I was doing it. The next step was to get some help on working out what a 'normal' daily diet was (I'd no idea by that time as it had been so long since I'd eaten properly, had no idea of what portion size should be) and teach my body to recognise 'normal' hunger and the 'satisfied' feeling rather than being starving or stuffed.
Having two small children is a HUGE drain on you, and working too, so you need to ensure your body is properly fuelled with energy and nutrients. If you can, ask your Dr to refer you to an eating disorder counsellor and / or nutritionist to tackle both sides of the problem.
In the meantime good luck, do your best to ensure you get the help you need, and have a look at the Eating disorders association website here
You are not alone - a frightening number of people struggle with eating, food and associated issues. Well done for asking for help, you've already taken the biggest and most difficult step.
((un-mumsnetty hug))