Hi, sorry to hear about all the awful heartache you've experienced recently. It sounds like this one is here to stay though, you're almost at the 12 week mark. I experienced one loss aged 22, and now I'm 24 and pregnant with twins. Just that one loss before made me extremely worried and paranoid, and I was convinced at every scan that it would be bad news. It's only now that I can feel them moving around that I feel ok about things. Didn't announce pregnancy until 4.5 months in.
My auntie had twins 6 years ago at the age of 44. She actually had a really straightforward pregnancy compared with mine, and her boys are very healthy. They were not fertility treatment twins, but a surprise
Anyway, tips to try and help your worries.. well, I spent quite a bit of money on early scans. I paid for scans at 6 weeks, 9 weeks and 16 weeks, and then from there, I was lucky enough that I get growth scans every 2 weeks because of having mono-di twins, but I'd have paid for more otherwise. You could also invest in a doppler so that you can hear heartbeat.
As you said, the rough symptoms are a sign that things are going well (although if you feel fine for a few days, it doesn't mean it's going badly either). I had horrendous sickness for about 5 months, and still get it sometimes now at nearly 29 weeks. Any symptom can be normal, for example cramping and bleeding, so try not to read too much into them and try to stay away from google!
Look forward to seeing your progress! xx