I have some good news and again it's all thanks to you guys - frida your comment about where the train stops got me thinking and it turns out that a suburb further away from the city, two districts along (so the 'wrong' way on the train), has a cycling club with regular group rides including for juniors. Now, neither me nor the DCs were big cyclists in the UK - I haven't ridden a bike since I was a kid - but it would be so good if we could do that together. The DCs could meet people too.
The next general meeting isn't for almost a month as I just missed one so I have emailed them saying I am interested in joining (so I can't wuss out), and have some time to practise and look out for cheap bikes for the DCs too.
Something I found out on the cycling forum though (on a post about whether it was possible to commute to the city from the other suburb), is that the area adjacent to ours is considered very dangerous. I feel I chose badly coming to this area but I researched loads and it wasn't mentioned anywhere 
I don't know what to do about DH.... my instinct was to share all this immediately, I would 'normally' do that, I tell him everything - or did. But now I am thinking (Charbon, thanks to your post), perhaps I could - should - just get on with it quietly. I think if H was sneery or negative about this (and he might be, make fun of me as I am rubbish at cycling etc and very unsporty), I would lose enthusiasm totally and it all seems very fragile atm.
I don't know what to do about the bank account - it seems impossible to open one in my own right here. My UK account isn't with a bank which offers an international service iyswim - so stupid of me. I can't see DH being galvinised into action on this issue either. I am going to do some more research.
Every time I get excited I remember Saturday. Jesus. I think the best way to approach it is to mentally prepare for leaving and make the most of the 'time I have left' here and maybe things will improve and I won't need to leave? Maybe? I don't know.
I have been feeling resentful, like why should I have to jolly myself along with no positivity from H - will he think that these things I am doing are for his benefit? I want to feel better and do more but if he says "it's much better now you are making an effort" (he talks a lot about my not making an effort), I would want to punch him I think!
Longdistance your post really resonates with me! We are all british too. I don't blame you at all for heading back to the UK and might well be doing the same. I wish I could get my head around what I need to do if I do... have nowhere to live etc.
I feel worse about DH now, crosser, but I think that I can channel it more productively... I hope so. The DCs are back soon and things always seem to nosedive then 