@kburra sorry to hear you're having problems with low iron.
I have an underactive thyroid (hypothyroid) which causes iron deficiency anaemia because my body can't absorb iron from food. Iron tablets never worked for me - couldn't absorb the iron from those either! So for several years now I've been having infusions every 12 weeks at a small local clinic. They insert the needle into my vein, hang the bag, and monitor me closely for the first 10 minutes as apparently if you're going to have a reaction to whatever they're giving you, that's when it's likely to happen. I've never had any kind of reaction and they usually leave me to it with a cup of tea, biscuits and a magazine whilst they see to other patients or just do paperwork. The infusion used to take a good 4 hours but the one I had in April was a new product (can't remember the name just now but will check) and it took only 30 minutes!
I know how very tired I get when I'm due for my infusion, and the difference it makes when I've had it, so am grateful for them. When I had the very first one though, some years back, my levels were so low it didn't make any difference at all and I had to have 4 over the year before I even felt human again, but once I settled into a regular routine it has made a difference for me.
Hopefully the pills will work for you but if you do need an infusion it's very straightforward and nothing to worry about. I hope you feel better soon.