Oh, I'm so sorry you're going through this. I had a similar experience - two scans showing way too small for dates, foetal pole had grown a bit at second scan but not enough and still no heartbeat, and still told I had to wait another week for another scan before they would confirm the pregnancy wasn't viable.
It did feel like torture and I remember being in tears and begging the EPU not to make me wait any longer, but they wouldn't budge. Got told they can't divert from their guidelines. It was horrible and I feel for you so, so much.
I ended up starting to miscarry naturally during that week anyway. Before that I just coped as best I could, one step at a time. I took a few days off work and we ended up going away for the weekend anyway, just so I could get out of the house (which meant we were further away from the hospital of course but I was past caring at that point, just trying to do whatever felt like I wouldn't lose my mind).
In a way I think the wait was harder to go through than the actual miscarriage, because you're grieving and you're in limbo at the same time. But I'm glad I got to do some of that grieving, even though I hadn't totally given up on hope. I also told the baby that I would understand if it couldn't stay any longer and if that was the case I was really honoured that it had chosen me just for that brief time, and it helped me a bit to get to say goodbye like that I think.