I would look up healthy and cheap meal options on google. I know Pinterest also has a lot of pins where you pay $150 for groceries and then make a bunch of healthy frozen crock pot meals, which could be a good option for you and would leave you with leftovers. Fruit wise, although it's less healthy than fresh or frozen, you could get canned fruit. Make sure that the fruit is in 100% fruit juice though. If you can afford a big bag of frozen fruit you could do a smoothie a day and it would last forever. Frozen veggies are really cheap and are actually better for you than fresh in most cases because they are frozen at their peak. $1 for a bag of steamer veggies can go a long way with 1-2 people eating it. Make positive switches when the price difference isn't very much (ex. if the healthy bread is 25 cents more that could be a good way to make a positive change without much cost). If you bought a bag of dried fruit you could make oatmeal (which is super cheap) and put the fruit in the oatmeal as a meal or snack. I LOVE apples (we buy bags of apples) dipped in peanut butter which is healthy and delicious. Sorry to overwhelm you, we have a daughter now and are on a tight budget so I've had to be a lot more conscious about what we have in the house.
Do you have an Aldi close by? We finally went to our local Aldi and we save SO much on groceries it's crazy! We can usually get a cart full for like $70. It's been way cheaper than Walmart even.
If you can't make it with those suggestions I would definitely recommend looking into programs for assistance. The reality is that although your is still inside you are needing to make good parenting choices right now, which is eating enough and well. That might mean you have to lay down your pride and get assistance for a short period of time but being a parent often comes with laying down your pride, so it will be good practice :). I would also recommend (if you haven't done this already) looking at what your needs vs wants are with your bills. Do you have cable? Could you switch to Netflix for $7 a month and cut that cost? etc.