Reestablishing milk supply. HELP!!

CAGMommy

My son is 5 months old and he was EBF. I just recently started weaning because he wouldn’t take the bottle and I plan on working soon. I would still nurse at night but I stopped, I would just pump and give him my expressed milk. I haven’t pumped in about 3/4 days and I’ve been giving him formula. I want to start pumping again, can this be done??? I normally drink Mother’s milk tea or eat lactation cookies.