First, I wanted to say good luck and congratulations! Second, as someone who had also lived abroad where I didn't speak the language and just *moved*, in general, over 15 times--yeah, this is something completely different.
I was a little different than you in that I dated DH for about five years (and knew him for six) before getting married and moving over, but we STILL had adjustment issues--and I had lived with him for months at a time over the years in between. Most of our issues centred around jobs (as others have mentioned) because the job-market here is...well, just as bad as anywhere else! It took me ten months to find a job. Any job. At all. Luckily, I love it and am well qualified for it, but, yeah, ten months--which was stressful (I am quite independent and HATED having to ask him for "house money" each month to do shopping and etc) and also just...morally depressing. I hadn't had a break from working since I was 15, and it was tough. I leant, a lot, on DH and while he was amazing the entire time, I know that it was less than fun to have a partner who didn't know how to turn the effing oven on! (Although I figured that bit out on my own!) or how to format a UK CV or exactly how to navigate the NHS (or Tesco...)
Is there a reason why a short amount of time as a long-distance couple is so distasteful? As far as building a career goes, it was my experience in the US that got me the job I wanted here, so the time I spent doing that was certainly not wasted, and I *know* that the time we spent slogging through the separations and flights and phone calls has made us stronger and more together than I would have ever imagined I would be with anyone.
Just something to think about--but, again, good luck! and congrats! And definitely keep asking questions here, it's an amazing resource.