The best way to improve your speaking is to speak :) You could try looking for a tutor or exchange partner. The former costs money, and the latter can be a bit trickier to find. You also must spend time helping them with their English (if you're doing an exchange). You could try finding "friends" online or in real-life (depending on your area). You might also want to identify issues with conversations. Do you have some sort of social anxiety or such that makes communicating in general difficult? Or that makes speaking in situations you're not confident in (such as speaking in Korean) difficult? If so, this could be a psychological, not linguistic issue. Do you have weak listening skills (typical for people who study on their own)? Do you lack adequate vocabulary? Do you struggle with grammar? Once you can pinpoint some issues, focus on resolving them by practicing, therapy, classes etc^^