How to translate "I have always been"
You have a few options. As @NS.X. pointed out 一直 is a good one, but you can also use 

一向, e.g.我一向很懒。I have always been very lazy. 

向来, e.g. 她向来就是个书呆子。 She has always been a bookworm.



从来 is more likely used together with 不 or 没 conveying negation, of course that is not necessary. 

A conjecture of mine: 一直 is often used with a certain beginning in the speaker's mind, which is not always pointed out of course. 自从饭后我一直忙的很。Since dinner I have been very busy.