Ok so having kids is a big change in the focus of a couples life and being honest, it sounds to me like your husband may be struggling with the shift in dynamics.
What you are describing as your "anxieties" sound normal to me, particularly for your first as it was unknown territory for you and so things will be more relaxed with the 2nd. And if you were overly anxious, it should have been worse with the 2nd during the pandemic, not better!
Coping mechanisms with babies differ, some say get them into a routine, its ok for them to cry but once you have checked they are ok, leave them to cry and eventually they will fall into a routine. You chose another route (maybe he wanted the first one as that is the traditional school of thought), massage etc, again just another personal choice.Neither us right ir wrong. I'd be anxious leaving my baby for a whole day for the first time and I'd check maybe multiple times, thats not abnormally anxious. But maybe he felt he should be getting your sole attention for the day and he struggles with your momentary priorities? People forget men struggle to adjust too.
Its common for men to struggle with the focus in the relation shifting from each other to prioritising a baby/child. And if when baby was crying and you choose to comfort baby maybe he saw that as you choosing baby over him, after all baby would be in a routine by now if you stopped massaging and we would have "us"time. Not saying its right but men struggle to watch on and cope with the changes too. Then you get a day at the wedding,again "us" time and you still prioritise baby. And what you are both doing is normal, both trying to find ways to cope but he needs to understand he is making this solely about you, he is possibly projecting his feelings onto you as he occasionally struggles with the shift in priorities
Back to now, so two days in a row you have gone out, doesn't sound like anxiety to me. Only you know if you go over the top with communication. If he was ill he was probably grouchy and struggling with looking after the kids but didn't want to admit it and unfairly felt when he got the text "crikey she thinks I am incapable of looking after the kids" and bit back. You showed simple consideration for your partner, he may have read more into it.
Sit down, when things are calm, have a chat and explain you were concerned about him, not the kids and wanted to know he was ok as he had not been well and not because you were anxious or checking up.
Maybe schedule in some more couple time.
This is all normal, run of the mill stuff and hubby is probably needing some tlc as you are BOTH still on a learning curve which will continue until you die!
Big hugs, lets us know how you go on x