Heavily regret leaving home

I recently did a company internal transfer to Japan, and while Japan is fine, I am realizing that I made a huge mistake leaving my home in the US. I didn't realize it then, but I am severely attached to the scenery, the food, the pace and way of life, the people I know, the office culture, all of it. I feel so isolated here, made worse by my poor language skills. And this resolution to go home ASAP has killed any interest I had in continuing to study the language.

I have to be here for almost 2 more years due to this contract, or I have to pay back a lot of the relocation costs. I also don't want to burn myself within the company. But I want to go home so desperately. I don't know what to do.