Lost weight in pregnancy?!

So I’m 7+4 and have gone from 186 pounds to 169 pounds! I was on a weight loss journey before I fell pregnant as I was 217 pounds when I was pregnant with my daughter at 17! That was just 12 months ago! Before pregnancy I was 84 pound so as you can imagine my body changed dramatically in just 9 months and my baby was only 4lb 😩 so I’m just wondering if it’s ok to be losing weight I’m super nauseas and completely off my food I can cope with a few slices of toast a day! Anything I can do?

EDIT HERES A Picture of before and after 😩 first pic is June 2017 second pic is April 2018, so just before I conceived!