Iron supplements

I'm so upset 😭😭😭 my Dr just cancelled my iron infusion and said I have to wait until closer to my due date to get it. I'm 29 weeks. I was so looking forward to getting it tomorrow and now I won't be getting it for at least a month. I get super constipated with the oral supplements and have been very dizzy and tired with the low iron but they didn't seem to care about how it is effecting me ☹️ I even cried when they told me. Help 😭😭😭