to check if your truss rod needs adjustment, do the following:
Press down the first and last fret on a string and see how far the string is from the 7th fret. it should just about be touching. If its pressed close or is high off it, then the truss rod needs adjustment.
It';s also possible that your first fret has worn down, making it lower than the 2nd fret. ideally, if the neck is fine, all frets should be the same size or smaller than the one before it.
Also check your intonation. it may be off. Take it into a store and make them take a good look at it to find whats wrong.
Putting the PRO and FAN in PROFANITY
-Agile Intrepid 8 String
-Kramer Striker 7 string FR
-B.C.Rich Afterburner SE Warlock w/ Seymour Duncan Blackouts
-Bassmaster 200W amp