Welcome, snork, and sorry to hear of your losses. Congratulations on your pregnancy and sorry you're feeling understandably apprehensive about the wait though the first trimester.
dorita is right, you're certainly not alone in this - this is one of two very well populated threads on MN filled with women for whom pregnancy or ttc is a very long slog emotionally due to previous miscarriages. I do take a lot of comfort that it's normal to feel as I do and that I can talk freely with people who really understand. I hope you'll find this useful, too.
I'm 7w5 after two early mc this year and my husband doesn't talk much about this pg either. I think we're both trying to think of it as a potential pg until we've got past 12 weeks, and it's just much easier for him to do that as he's not got lots physical reminders of how real the pg is now.
Are you sure your local EPU can't scan you any earlier than 12w? Mine is very happy to give as much reassurance as is needed through the first trimester and there's good evidence this can actually improve outcomes. Do see what you mean about a scan being no reassurance until the next scan, though, given the history of your losses. But since odds of m/c decrease vastly after hb, after 8w, etc., I'd still find some comfort in knowing my chances were improving.
I hope it feels easier for you soon. If it helps any, I've been surprised by how quickly I've gotten to (nearly) 8 weeks and I felt just as you do when I found out at 4w. Take care.