@WhoAteAllthePercyPigs I understand how you feel. When I found out DD had to wear a harness I cried and cried thinking I had failed her! I want to reassure you that the harness doesn't hurt babies at all, it just goes on underneath their clothes.
Each hospital has a different view on how strict to be with the harness. My hospital is very strict, we aren't allowed to remove the harness and will have to go every week to that DD for a bath, harness removal and for her to be measured.
They have said that time period for the harness will be 4-6 weeks but not to get upset if it's a bit longer. We will have another ultrasound towards the end if that time to see if she needs to extend the treatment.
The harness is made of fabric, I have found it much easier to hold DD upright since it was put on. And nappy changes are easier as her legs are already held up - no more feet being dipped in poo.
Initially we had a scan when DD was around a week old, but they doctor who scanned her said this had been done too early as she was 5 weeks prem so therefore not actually there yet and it was too early to tell.
This reply has turned into an epic essay which jumps around. Please feel free to ask as many questions as you like. The important thing to remember is that our babies won't remember this time in the harness but we are setting them up for the rest of their lives.