It's actually quite likely op was taking 60mg. In my country they start you off at 20mg and if that doesn't work they increase the dose. If you can take up to 70mg with no real result they pivot to faster acting substances.
The adhd brain that sees results on 60mg would become able to focus "normally" for a "normal" amount of time, get tired as usual, then go to bed at a regular hour.
A lot of hyper productivity people take more than the therapeutic dose but the truth is more complex. Medication that can "fix" the executive function in a lot of adhd brains for a brief period will do crazy things for a non-adhd brain for a longer time, because the non-adhd brain doesn't require fixing or support in that way.
The adhd brain that sees results on 60mg would become able to focus "normally" for a "normal" amount of time, get tired as usual, then go to bed at a regular hour.
A lot of hyper productivity people take more than the therapeutic dose but the truth is more complex. Medication that can "fix" the executive function in a lot of adhd brains for a brief period will do crazy things for a non-adhd brain for a longer time, because the non-adhd brain doesn't require fixing or support in that way.