I can't quite get my head around the idea of being anxious of having two kids solo, but I'm not judging.
Based on what you've said previously, I'm assuming you've got one under 1 and one around 2/3. I have 17mths between mine, so practically speaking, things that worked for me were;
Getting into the car. Carry baby, hold toddler hand, put baby in their seat (one handed, still holding toddler - baby seat is rear facing so they're not going to fall onto the floor), walk around car, wrestle toddler into seat, return and fasten baby seat belt. In reverse, the baby is probably in a stroller so you can leave them strapped in while you get the other in. Basically, always have the most mobile child restrained the longest!
Shower. Either do it mega early while husband is still home, or 1 in a playpen (either the eldest to contain them, or the youngest). My eldest went through a phase of watching iPad for the 5mins it takes to shower.
Get them sleeping at the same time. Even now, 1pm is 'in your room and rest time' here. They had stairgates on their rooms at one point to contain them. Bedrooms should be safe so they can play independently for a bit. Get them sleeping, or playing, for an hour at the same time, is an hour to do a few chores/prep dinner/drink coffee. I watched TV and prep dinner 😀
My husband is generally home to put the kids to bed, so I use time them to hoover, tidy the carnage from the day etc.
TV is a wholly acceptable short term babysitter! 20minutes of paw patrol is time for coffee.
Have a routine and a plan for each day. You can organise all the required stuff the night before, then you just need to get up and out.