Upsy, sorry, I'm a long time lurker and have read the whole thread. I can see you're in a difficult situation, but I hope not insurmountable.
It's been a while since you posted and I hope you are o.k.
You've had a range of opinions on here, but I agree with many posters that you need to find someone in RL to talk to about this outside your relationship. You are talking about making huge decisions (I'm sure you are excruciatingly more aware of this than me...) and much as MN is a handy sounding board, we don't know you or your partner.
Please find someone to talk to in real life, be it a friend, relative, Relate worker, GP, HV, samaritans....
I can understand your confusion and worries for you and your young children but this is too big to work out online. This could all be salvagable, or not, but we are not in the position to judge.
I wish you all the best for you and your family and hope and pray that you've found someone helpful and supportive to talk to .......