You said "the tiredness has always been there." So I am guessing that it was there before you started the stim meds? Tiredness is a know side effect of effexor if too much is being taken. Now that you are on a stim med., it hopefully is reducing your anxiety somewhat. You might want to talk to your doc about reducing your anti anxiety medication. Do you have the same doc for both the concerta and the effexor?
Note, Concerta should last about 8 hours while the Vyvannse could go 10 to 12 hours. Also Concerta is a Methylphenidate, while Vyvannse is an Adderall based med and is stronger. You might want to try the Vyvannse again, but increase the dose slower. Typically tiredness is not a side effect of stim meds, unless you are over dosed and then you can feel kind of stoned.
Hopefully, this helps a bit. Please ask if you need more info.