Be thinking of you at your scan tomorrow emvy
Staying sane you say? 
You go a day at a time. Keep busy when that feels right. Rest when you need to. Allow yourself the odd session of uninhibited sobbing under your duvet (mother's day nearly levelled me this year!). Lean on your husband/partner and any friends who get it.
Several months on I find myself worrying less about the long term and probably worrying less generally actually. I have moments of paralysing fear about never getting my baby and not ever been a Mum. About yet more losses, pain and trauma. But they don't last long!
Find what comforts you, and do it it.
For me I got a bit into crystals and I cook a lot, others have church, mindfulness, mediation, walking.
It's not about blocking it out, but trying for a balance between honesty and letting your feelings out when you need to, and staying sane and functional the rest of the time.
As a stepmum I'm a stuck between the good and bad bits of not having children, and then having part time children. No baby to snuggle and be grateful for, not much time, money, flexibility to let loose and enjoy the lack of responsibility.
I want children of my own as I'm already living the life of a parent every weekend, and DH wants more because he knows how great it is and he desperately wants them to have siblings. Sometimes I think it's worse for me as he's already a dad so has lost less. He thinks that's unfair and while the physical losses are mine the emotional losses are the same, plus his additional worry about me.
So when we need to we talk, and talk, and talk and talk some more.
We're still laughing, having fun, shagging both in and out of the green week, drinking moderately, making plans, looking after each other.
I've found reading other people's experiences has helped, to see how someone else expresses what you struggle to put into words is reassuring.
After 3 losses you end up under a RMC anyway (we're on 4 now) and for us having a plan, whether or not it'll work, is something hugely positive too. I'm not actually convinced as they haven't found a cause in either the one baby they tested or me, so how can they really fix it. But our guy has good results so travelling hopefully.
Having you lot to talk to helps an awful lot! Maybe knowing some of it's not sane but is still totally okay is the most useful thing of all
xxx