Low Ferritin - when did give up on oral iron supplementation and ask for an iron infusion?

My ferritin test came back at very low end of normal according to my doc (my CBC panel came back normal). I’ve been instructed to take 65 mg of iron supplementation/ day. They recommended Megafoods Blood Builder (which I learned only comes in 26 mg tablets). I’ve been on 52 mg of blood builders iron for about a week and a half (taking on empty stomach per instructions). I have a weak stomach and am getting an upset stomach (not unbearable but not great). Already over it. For those of you who have had stomach sensitivities to iron supplementation, does your stomach adjust over time?

For those of you who get iron infusions, why did you go that route and how difficult was it for you to get a prescription for the infusion? Does my iron have to hit rock bottom to even stand a chance at getting a prescription and insurance coverage? Did you experience any side effects from the infusion? Thank you for sharing your experiences!

(FYI - I’m 53 and am on HRT .0375 mg 2x/week estradiol w 100 mg of progesterone that I take vaginally because I don’t tolerate it orally. I’m at tail end of peri and having pretty erratic periods that are lasting shorter or longer than usual and sometimes 2x a month or maybe skipping a couple of months. This has been the situation for the past year-ish. I was anemic after a difficult child birth years ago and how I’m feeling now is vaguely familiar.)