Yes, without a single doubt, yes. The truth is always worth telling because it can not remain hidden no matter how deep you bury it. Yes, it can be difficult and painful but if you come up with a beautiful lie to keep yourself or the other person from hurting, you're only delaying and doubling the pain that comes after. Short-time happiness or comfort is never ever worth the long-term grief that hits you like a truck later on in life.  

I wouldn't falsely claim and say that I've always been truthful. I haven't, but if there is anything I have learned from those times it is that the truth finds its way out. 

I do see why you felt the need to ask this question but I think in most cases, the truth is always worth telling. As a matter of fact, there is only so far you can get if you keep hiding the truth.  

Nonetheless, there are exceptions to it as well for e.g. if your lie can save the life of someone who is in danger then the truth isn't worth telling at all. Similarly, if a white lie can put two people back together, what's stopping you?  

The times other than this, you shouldn't hide the truth at all.