"I have so much to say to you but I'm so nervous right now" "nervous" doesn't seem to have a perfect match in Korean. It might be translated as (신경이) 과민한, 소심한, 불안한, 안절부절 못하는, 떨리는, etc. In sentences like the given one, 떨리다 (afraid, tremble) or 울렁거리다 (feel squeamish) seems to be a good fit. So, 너한테 할 말은 무척 많은데 지금은 너무 떨려서 못하겠어. (casual style) Or, 네게 할 말이 참 많은데 지금 너무 울렁거려서 안 나와.