Hello degreecollector, I don't know if I can be of any real help as I am in the exact same position at this point in time! Returning in September/ October from an interruption from my PhD and feeling really lost and 'dumbed down'. I hope you aren't feeling despondent like this!
I have spent some time doing some goal-setting, however, and this is starting to help me rekindle my motivation (and reacquaint with my placeholders; where I last got up to with my research project and what was left unresolved at that stage which I can pick up from here, rather than from ground zero).
Don't know if that's of any use as a potential strategy to start with, but at least we can keep each other company as we transition back to studying, with this thread perhaps?
PP xx