Im not to sure if there are any drugs that will help, While you are recovering your body will need time to heal, This maybe a long precess. Getting pregnant may be difficult while your body is still healing. Try waiting for a few months, 6-12 is what it takes a healthy couple to get pregnant things may take even longer in your case.
you need to make sure your body will be healthy enough to look after you and a baby growing inside you, This is going to be a big challenge for anyone.
All the best
Sarah

I do not know of any drugs that can help you get your period back per se. There are fertility drugs that can help with ovulation. Talk to your gyn about your concerns. Make sure you are fully recovered (and I don't mean recovered as in going back to anorexia, I mean make sure your body is fully recovered from any potential damage that may have been done)and look into seeing a fertility doctor if you need help stimulating ovulation.