Yes, I agree with larrabee about everything but the cut your losses bit. I read your post and am very sad for you that things are not going well so early on. I know that LDR is a whole different beast than dealing with someone in person...actions speak louder than words and such...but you two shared a strong connection that resulted in marriage. I'm sure that many married couples here could comment on their experiences and give you advice on how they dealt with their differences long term. Don't give up, you guys fought for something special for so long with all the long distance, see if your wife would go to counseling with you? I'm sure a professional sees your exact situation regularly, and can give you both some unbiased tips on how to communicate better and resolve your disagreements.
And yes, just update the papers yourself, insert new documents, write the letter yourself....if your solicitor thinks that biometrics forwards the docs for you, wouldn't trust him though. I know it feels better to have a professional check things over (I know at times I debated about hiring one)....but yes, you have the hard part done (knowing what to submit and a template), updating it will be easy.
I'm a cynic as well, and if this were a regular relationship, I'd tell you to bail. But you have to step back and take a moment to be rational. Major life changes are stressful, even if they're fun/positive in the end, and the toll here is manyfold, with the prospects of a new marriage, actually living together, moving countries, giving up all that's familiar, losing a measure of independence, etc. Yes, it is a rough patch. But it'll remain a patch only if you get a grip on it now. Otherwise, it could turn into a rough ocean (or other large expanse, take your pick).
I'm moving for good in 10 days, and I realise my situation's different from yours in that London makes it easy to go out and do things and I've got established London friends (who aren't my husband's) across a wide variety of my hobbies and interests, but that doesn't mean I'm not feeling the effects. I've improved at spotting when I'm coming down with a nasty case of the overwhelms, which means I can say to the Gentleman Husband, "Dude, cancel tonight's Skype date, I need to lie on the sofa like a slug and watch horror movies instead." It prevents my snapping at him over something innocuous just because I'm feeling more than my customary two emotions and don't know how to handle it. We're being extra-flexible these days because it's such a high-stress time and because we'll be together soon enough (also we exchange a lot of rapid-fire emails during the day).
Take some time to cool down, then step back from the trees a few dozen paces so you can see the forest. Have a conversation with the knowledge that you're BOTH experiencing major life changes or the prospects thereof — and, importantly, that one person's stress isn't any bigger than the other's, it's just DIFFERENT. Otherwise you get into a cycle of one person feeling guilty that his/hers isn't as "big," so he/she "shouldn't" be so stressed. Bollocks to that. In a normal relationship, you get to deal with this stuff gradually, in an LDR the haymaker of change lands right in your faces. Repeatedly.
Better to just admit going in that you're both on the mat right now, then take a deep breath and say, "OK, how can we best support each other in our stresses, and what — realistically, rationally, honestly — is the best place/situation for us, as partners in life, a year from now?"
Aaaaaand ... end unsolicited advisory ramblings.