How to prevent iron deficiency once and for all???

I keep becoming deficient and it sucks. I was vegetarian for ten years, but after pregnancy I decided to start eating meat again to help keep levels up.

I don't eat that much red meat which I know is higher in iron, I eat mostly chicken. But again I am deficient and booked for an infusion.

I'd love to maintain those good levels after treatment. What do you guys suggest? I have been on a supplement for two months which made ferritin go up maybe three points, so not great.

I also ordered one of those iron fish which you cook with that leaches iron apparently. I may try the beef liver caps again as I had those for like one month. Plus try and eat beef more often. But idk how often? I should probably see a dietician.