Exactly. He has told the OP but she's unwilling to accept his views. That's not fair to the dh.
OP, I do feel sorry for you that you feel unhappy with your situation but you have to make decisions for yourself, you can't force another person to do what you want. Your dh has told you that he'd be unhappy returning to the UK, he seems happy with the life you've created abroad and you have to accept that.
What you can do is decide whether you want to seperate/arrange custody and then you move back to the UK and take on all that goes with that (a lot of upheaval for your dc flying back and forth between the 2 countries to spend time with each parent for example) or, change your mindset about living abroad.
Why exactly are you worried about your future there and why now? This must have been something you thought about years ago when you first settled there so what's changed? Think carefully about what you'd like to have in your life with regards to work, friends, social life etc etc and if you don't currently have what you want then what steps can you take to make it all happen there? Retrain for better work opportunities? Improve fluency skills if language is a barrier to better work opportunities? Join clubs to make more local friends? Travel to the UK more often to see your parents or ask them if they'd like to live in your country?
Fwiw, I wouldn't want my dc going to school in the UK. I love my parents very much and I'd want to help them as much as I could but, if I was in your situation, I wouldn't try to force my dh and dc to move country to be near to my parents, forcing them to leave behind a life they were happy with.
If you've been away for a long time, how do you know you would be happy living in the UK?
I hope you find some peace and happiness OP. If you come back to the thread and give further info maybe posters can help you find a solution that is reasonable for everyone involved.