Advice on sleeping alone for the first time in years?

I know I probably sound silly/crazy/immature but my husband and I have gone to bed together every night (give or take a couple) for over 7 years. His work recently switched him to a different shift so he could train a new group for the next three months (then things will be back to normal). So he used to leave for work around 4/5am and got home around 5pm and now he is leaving the house at 3pm and getting home around 4am.

I am finding it SO VERY difficult to fall asleep when he's not home. My whole routine feels off. It's been almost a month and I have yet to go to sleep before 2 am. We have a 15 month old and I'm 8 mos pregnant so I obviously can't be missing out on what sleep I can get. I am dead tired by 9pm but I just toss and turn in bed usually until he gets home. We are incredibly boring and routined people so when there are big changes like this it's not very fun however the extra money just as baby comes was too good to pass up. Part of me isn't used to sleeping alone (and it feels weird and I can't get comfortable) and the other part likes knowing he is okay and safe (45 minutes commute on a highway at night worries me 😖).

It might be a petty/small thing, but I would love to hear any tips or advice for how I can feel less anxious at night or have an easier time falling asleep.