^I agree. Just find a single syllable short form of your own name. For example, if your user name "kkwonhyeokk" was your name, just try introducing yourself as "Kwon" (unless that's something rude in your mother tongue!). If you just want something easier for the locals to pronounce, that would be fine.
Brits don't expect overseas students to have English-sounding names, so don't bother about trying to fit in like that. In any case, British names are often shortened to a nickname (Will for William, Steve for Steven, Liz for Elizabeth etc), so it's a very common thing to do.