Im sad to read this because I understand exactly this situation you're going through. What I did was I switched to eating more plant based food but I was very conscious to keep protein. It's not enough to eat plants by themselves. You need fat and protein to live healthy.
I say lentils and rice is a good option. Calories dense and complete range of protein. Beans and rice etc. I also eat yogurt drink milk etc and eggs rarely. Meat and chicken rarely and it's been like a year since I ate fish of any kind except rarely as well done canned fish .
I'm so sad to give advice for this. I pray you never had to live in such condition but I am afraid soon nothing will be affordable. If I was ever to attack the evil people who did this to us I would do it for people like you.
I hope you get through this. Please don't give up