Need Some Advice Regarding Paul Mitchell Special Shampoo

Hi! So as the title states I am in need of some help regarding shampoo. For hair context I have an itchy scalp with roots that get oily fairly quickly and ends that can either be dry or not (usually not depending on conditioner) and hair isn't thick but not super thin either and I have been noticing that it seems to be getting a bit thinner recently.

In December of last year I switched from Paul Mitchell special shampoo to Head and Shoulders for itchy scalp with eucalyptus because my scalp was getting so itchy and the Paul Mitchell wasn't helping anymore.

However I bought a bigger bottle of the Head and Shoulders in January and now all of a sudden my hair never feels clean. I have no idea what happened but I need to switch shampoo's again, but here is my dilema, I've heard that Paul Mitchell changed their formula (the last time I bought it I'm pretty sure I got the original formula) so I'm wondering if it's worth switiching back to or not. Has anyone noticed a real difference in the new formula? I'm really at a loss for what I should do, so any advice, recomendations or experences would be great!