Losing weight

Hi. I’m overweight (bmi of around 40). I’m 9 weeks pregnant but am struggling to eat - due to not fancying food due to nausea and also anxiety which makes me not want to eat. I have really bad stomach/hunger pains but can’t face eating. I can afford to lose weight but don’t want it to affect the baby also concerned that my only source of nourishment is my prenatal vitamins as not eating healthy foods like fruit and veg only really carbohydrates. Looking for advice on a) whether lack of eating is a problem for baby and b) whether lack of good foods is a problem for baby. Thanks in advance.