Question for mama's with previous losses

Backstory: I turned 40 in june, and this is my 3rd pregnancy this year, I had a loss at 11w4d (although I believe that was a missed miscarriage, and the baby stopped developing between 7-8 weeks) and a loss at 6w2d.

I'm scared to let myself be happy. Hubby and I already agreed we don't tell anyone until we hear a heartbeat, and then it will still be very few ppl until out of first trimester or maybe even until anatomy scan.

We have a little that turns 2 next week, that we never thought we'd have, as previously I was diagnosed with unexplained infertility since it took over EIGHT YEARS of constant trying before my first ever +hpt which resulted in him. Since then my body seemed to kick it into high gear taking just a under a year to get pregnant again and then just 2 months after each loss I'm pregnant again.

Question: how do you remain calm and not let you anxiety take over, how do you celebrate your current pregnancy without the worry it's just going to be another loss?