How do I know how much to eat ?

I am in recovery, and I know people say to eat as much as you want. But I feel such a lack of control and feel anxiety when I am done eating and still want more- I feel greedy and like I don’t need “extra” or that maybe I’m full. I never know if I feel truly full and when to stop. I get so nervous taking more food. Tips appreciated please and thank you 💕