Try not to panic.
Suddenly scrabble around for “documentary proof of a relationship”. This can be: ticket stubs, flight itineraries, Skype call records, photographs. This cannot be: late-night explicit Skype chatlogs, half-finished erotica, a nagging sense of loss whenever you leave each other.
Somehow amass £2,500 in savings from a job that pays you £6,000 a year. Do this by obsessively accounting for every expense, continuing to live in your parents’ house, and taking on extra work whenever you can.
Really, don’t panic. It’s going to be okay.
Go to London and pay £227 for a doctor to examine every part of your body, including but not limited to a chest x-ray and careful inspection of your genitals. Pay another £150 for vaccines that you would never need in the UK, including but not limited to rabies, rotavirus, and hepatitis B.
Pay another doctor in America $20 to look at your newly-completed vaccination records and copy them onto a form, then put it in an envelope.
Get used to doing everything in triplicate.
Get used to waiting.
Make vague plans for the things you can plan: getting a US driver’s licence, a rough picture of the job market in the US, where you’re going to get married. Try and keep them as firm as you can without over-planning.
I mean it, panicking solves nothing. I know that living and breathing bureaucracy for two years of your life isn’t what we in the business call “fun”, but there is an endgame here.
Try and remember that other people are going through this process because if they don’t, they’ll be executed by authoritarian governments.
Don’t deliberately go looking for horror stories on visa forums. Keep in mind the statistics - that, taking into account appeals, 99% of the people applying for this visa have it granted. Which, given that it’s also the visa with the highest rate of fraud, is not a bad statistic.
Try and gently loosen ties without severing them altogether. Gear up for departure. Don’t obsess over what you’re leaving behind, but don’t ignore it either.
Remember why you’re doing this. Remember that a few thousand miles away is the person who changed your life, who makes you laugh more than everyone else you know combined, who inspires you to work harder and make art in a way that no-one else does, who is so jaw-droppingly beautiful that you sometimes need to pinch yourself when you’re in a room together.
Don’t allow a mountain of paperwork to distract from essential truths, like the fact that buried under that mountain is love so impossibly solid and secure that you’re amazed it exists.
Keep in mind: a green card is just a means to an end, and that end is fantastic.