dude, im not here to worrie anyone but, Psych, these are sympthoms of substance abstinence, it is normal, even that can happen with less amount of stimulant, nicotine alcohol or any other substance, dont be worried, i think 70mg of lisdexamph equals to somewhat of 30 mg of dexamph, so dont be worried about the dose, in a clinical context lets say it is quite harmless. Do not raise it ever higher than prescribed, you could have serious issues like, if done that on a regular basis, medication could not be working again with lower doses.
As I said, I dont want this to be understood as a moral reprimend of any kind... but watch out, with that doses of caffeine or ritalin said by Hyperagitate the most common thing to happen would be death. In fact i dont know how you even survived, i went to the hospital once with much more less caffeine than him, (600mg) and i dont wanna try methylphenidate over 54 mg.
The only thing that could happen to you if you go over that ammount on a regular basis is your ADHD to turn MUCH harder to treat, or even turn impossible to treat at safe dosage, not to mention you could go on a psichotic trip, that could even lead to schizophrenia, or even trigger mood disorders that could last your lifetime.

Dont be worried to treat your ADHD with safe well docummented dosages, such as you, Psych, are taking, talk to your physician if you have any concern, specially related to tolerance, medicine working worse, mood changes, personality changes.... but do not self medicate, or rise your dosage above 70mg of vyvanse, or even more without talking to your doctor. You could have serious non-comfortable issues at all, you could be damaged for a lifetime.
Do not forget these are stimulants normaly 2 times strongers than coke, noticed that relationship in this matter by coke abusers them selves, there several studies about this on the net, serious studies in fact. Ritalin could not be distinguish from coke, do not play with your health