Sindarin for "I must leave/I must go away"?

I've been searching the dictionary but haven't found a Sindarin equivalent for "I must", either a suffix or words. Can someone help me find or make a translation for it?

ᴺS. [N.] ^boe [mb-] v. “I must” it does not conjugate. Probably Boe haenon.

I might rephrase it as "I need to leave." Bauron haenad. ᴺS. !baura- [mb-] v. “to need, require”.