I have the exact same issue with my concerta. Patriot makes the alza pills, and Mallinckrodt doesn’t. I recently had a refill and didn’t notice my medication working at all. It was the Mallinckrodt manufacturer. There isn’t much you can do but try and figure out when your pharmacy stocks the specific manufacturer. My pharmacy usually seems to supply the manufacturer I like near the end of the month. If you are close with your pharmacist you could ask them to notify you when the manufacturer that makes the alza pills is stocked. But believe me as someone who has been on Concerta for many years it is NOT in your head. If your pharmacy doesn’t stock concerta from different manufacturers, I’d suggest switching pharmacies, especially if you have found a medication that works for you.
I wish you the best of luck. It is not all in your head.