If you dont like life in the UK even when you are on an extended visit, then I would be quite sure you wouldnt like it if you moved permanently (or even for 2-3 years).
I think its important to realise that becoming an expat, living in a new country, etc isn't for everyone and you should consider yourself lucky that you have realised this before you made the big move. We have heard from so many unhappy people complaining about everything from laundry, shopping, showers, pub culture, homesickness, small houses and IME, these people never really grow to enjoy their experiences here.
I can't speak about a long distance marriage as I have never known anyone in such a situtation, but I most certainly wouldnt do it myself. Although, this doesnt necessarily mean you dont love him enough, it may just mean that he/the situation isnt the one for you. You can love many people in your life, some even deeply, but that alone isnt enough when the situation is all wrong.
Best of luck to you in whatever you decide.