Korean: 죄송합니다, 한국어를 연습할 시간이 별로 없음니다.
Romanized: jwe-song-hab-ni-da, han-gug-eo-reul yeon-seub-hal shi-gan-i byeol-lo eob-seum-ni-da.
Pronounced: jweh-song-ham-nee-dah, hahn-goook-uh-reul yuhn-sub-hal shee-gahn-ee byuhl-loh uhb-seum-nee-dah.
Literal meaning: sorry, I don't have much time to practise Korean. (It sounds more natural this way)
Note: I assumed you were looking for the formal form because you seem to be trying to apologize.
And 'goook' in the pronounced part is a deliberate typo. It should be a 'double o', not triple. Apparently Yahoo! thinks 'g o o k' is a swear word. I don't know why. (I've never heard of that word)
OK... you could have said that to start with. It would have made my life a little easier. :)
Here's the informal form:
Korean: 미안, 한국어 연습할 기회가 별로 없어
Romanized: mi-an, han-guk-eo yeon-seub-hal gi-hwe-ga byeol-lo eob-seo
Pronounced: mee-ahn, hahn-goook-uh yuhn-seub-hal gee-hweh-ga byuhl-loh uhb-suh
Literal meaning: sorry, I don't have a lot of opportunities to practise Korean
Is that better?