Hi OP, sorry to hear you’re feeling trapped.
From the way you describe your job, I don’t think you’d be happier if you returned. What you’re remembering is your pre-child days when your priority was yourself. You could be on long-haul flights then etc etc. But the fact is, things have changed. It’s no good expecting you can waltz back into your previous job and feel no guilt or separation anxiety about being in different continents to such young DC. It is what it is. You’d just be replacing one form of stress with another, realistically.
Can you look at it this way - you are in a privileged position to be able to not have the pressure of working. This is a fact and a privilege that most women will never get to experience. It’s not forever. It’s a point in time. I know how easy it is to get into a deep rut. It may be you are suffering from PND, so please see a GP about this. It can happen to anyone.
In short, nobody can be the mum they want to be if they’re burnt out. You HAVE to learn to take some time back for yourself. It doesn’t have to be anything dramatic, but just some fixed points in the week when you can recharge. Babies are relentless and when you’re worn down you can’t see the wood for the trees.
I was in a similar position to you in that I didn’t have family around and also I didn’t feel comfortable leaving them with a nanny or childminder. I knew how hard it was and didn’t trust anyone else to do it. But I started off in a small way. There was a time when my youngest was about one and I used to get someone to just play with her for an hour in the afternoons when I went in the school run for the older two (otherwise the baby would fall asleep on the school run and then be up until 10pm). Gradually, this lady (who was from the nursery) stared coming a little more often if I needed to just do something “hands free.” I remember just walking out the door without the buggy and at least one of the kids used to feel like I was walking on air! I would just go to a coffee shop and post crap on MN 
. Or meet a friend or go for a swim.
Basically, as a SAHM you have the freedom to make the day what you want it to be. Don’t put pressure in yourself to feel like you SHOULD be doing x,y,z. Looking after to mini humans is enough. Get a cleaner in. Meet up with friends and their kids as much as you can. Summer is coming and it won’t be long before your younger one can go to the nursery for a few mornings. Then can come home and do exactly what you want.- max out when you can basically. Even if you just sleep. It really does get easier. If you can manage to do something physical, yoga or running or swimming, it helps so much. It’s a cliche, but you'll never get this time back, so try and make the most of it and take enjoyment from the small things. Be kind to yourself.
Maybe tell your husband how you feel and just book yourself into a hotel for a night. Then come back with the priority of creating a better balance eg in your life. I wish you all the best!