start feeding right away mate, that soil is very mild,... keep the soil moist always, a little surface drying is OK, normal in fact but not deeper down... Roots are unhappy, it'll take a while and a set or two of new leaves to get back on track...
Drooping could be form both over and underwatering, ironically! ...But for entirely different reasons; overwatering and soil saturated for too long smothers the roots, O2 starves them and they die off,... best you can do is try to keep things evenly moist while they recover,... what nutes do you have? Start out dilute for sure,...