How old are your children at this point OP?
How old are you and your husband? These questions ARE relevant.
If we were to assume that your DH was on board with the idea, what exactly do you think would be different out there? Bearing in mind that you've been in the UK for a long time now, do you think that the support network that you're longing for, would actually be not only willing, but able to be there to support you in the way you would like? Have you talked to them about it?
You say you would like to be there for your parents as they get older, but what about your DH's parents? You may get what you want out of a move, but have you thought about what it would be like for your DH? He may be homesick, miss his friends and family, and it would also be worse for him because from what you've said, he doesn't speak the language.
I really think that you have to ask yourself whether you are prepared to lose your husband, in order to return 'home', as having lived here for so long, and married him while living here, you really are asking an awful lot of him, as presumably he thinks that you're settled here. However, if you're adamant that you NEED to go back, then it's obviously going to break up your family and lead to divorce. Is this what you want? How would your children deal with losing their Dad? Would he agree to you taking them out of the country with you?
While I truly can understand your feelings OP, I do think you're being very selfish, as you're expecting not only your husband, but your children to leave everything they know, on the off chance that you will ALL be happy in your home country, when you have absolutely no guarantees that even you will be happy there.
In reality, I think you need to tell your DH how you feel, as he may be happy to at least consider what you want to do, whereas if he doesn't know, and you continue to keep him in the dark about something which is clearly important to you, it's likely to breed resentment in you, which won't be good for your marriage.
Then, if he says there is absolutely no way that he will consider it, and would NOT let his children leave the country to live with you, I think you need to work out what you can change about your life here, in order to help you get over these feelings, and help you settle down again. For example, do you work at present? If not, then perhaps look at getting a job, as you may be feeling a bit like you've lost your identity, ie, you're a wife and a mother, but who exactly are YOU? Could you work on building friendships with people who would be prepared to babysit, so that you and your DH can have more time as a couple, if this is an issue? Could you develop some new hobbies to make you feel more fulfilled? So many things for you to consider, but life really is what you make of it OP, so I think you need to work out the real reasons behind your desire to go 'home', possibly a therapist might be able to help with this?