So sorry for your losses MouseLove and user 
No one understands better what you're going through than the women on here.
user I had the same thing with a MMC diagnosed at the 12 week scan. There's nothing like the shock and awfulness. I ended up having an MVA as the medical management didn't work.
I bled that night but it stopped the next day and then nothing till my first af 4 weeks later. I had some pain for a couple of days which then got loads worse 4 days later and I ended up in a&e where they gave me antibiotics for an infection.
They weren't sure what caused it but I was feeling better a day or so into the ABs and it wasn't that bad. By then I was just weak and shattered I think so rested loads, ate lots of fruit and veggies and drank water, took vitamins etc.
We waited a month then cracked on and I got pregnant again straight away but looks like I'm going to lose this one too.
Mouse, it all sucks, there's no way round it, it's shit and I'm sorry for what you're going through. I can imagine your panic about having to wait for the thyroid specialist but get your MRI done and, as you say, get yourself fit and well again so you can be in the best shape for your next pregnancy.
You've been through a lot, so don't jump into a mad fitness regime just yet. It takes a while to stop being pregnant and to feel normal again. You don't get to 9+4 and then suddenly stop being pregnant, your body's been through a lot with carrying your baby and then your miscarriage so look after yourself and go easy.