So sorry for your losses...all of you
I am currently 29+2 after a MMC last October. We found out at 10+3 that baby had died close to 6 weeks, then it took almost a week to get the D&C, which was 10/31. Christmas morning we found out I was pregnant again, and it was honestly about 30 seconds of overwhelming joy followed by weeks of panic and anxiety. Like with you, sailorsgirl, I had all my symptoms with the MMC- even went to my first OB appointment with a plastic bag in hand I was so nauseated- little did I know baby had died weeks earlier. So my symptoms were of no help to me.
At 8+5 with this pregnancy, I hemorrhaged in my bathroom and thought that was the end- only to discover I had been pregnant with twins. Somehow even knowing that there was still an alive baby in there didn't help, and I spent 5 weeks on bedrest waiting to lose that alive baby also. At 9 weeks, I was able to find a heartbeat with the doppler, and then proceeded to use it 3-4 times a day. I was a little obsessed, and every single time would take a short video on my phone in case it was the last time I heard it. I know that sounds a little morbid, but after never having heard the heartbeat with our MMC, I felt compelled to have some "proof" that this baby lived.
Around 12 weeks and several follow-up ultrasounds later, I began to be able to breathe a little, and finally around 16 weeks I felt comfortable enough to tell people I was pregnant (plus I was starting to look a little plump, lol)
I will be honest- I didn't really actually truly begin to relax for real until viability, not even after he started moving regularly. Now that I'm in my third trimester I'm starting to breathe a bit easier and it seems like pregnancy has somehow passed in the blink of an eye- I guess time flies when you're obsessively anxious about it, right?? I admit to having occasional thoughts of "I wish I could just have him out now, early would still be better than having the risk of my own body accidentally hurting him" but I KNOW that logically that's not true and the best place for him is right where he is for a couple more months.
So to actually answer your question, I think that the thing that was most helpful for me really was just knowing I wasn't alone- other womens' stories of pregnancy after MMC helped a lot, and talking to my best friend (who went on to have two beautiful healthy babies after MMC). Interestingly, my husband and I basically didn't even acknowledge the pregnancy to eachother until nearly the second trimester!