My doctor prescribed me vyvanse 30mg 2 months ago, will i build a tolerance to it?

Only after a time: The usual starting dose of Vyvanse is 30-40mg. At your next visit; if you are still not having benefit, your dose will be increased. After 50mg & 60mg, the maximum dose is 70mg each day. At a certain dose, you will have significant benefit of focus and task completion without side effects -- that's the dose that you may be on for years go come.