Low milk supply and current left 1 drop of milk can I still pick up my milk supply again?

Yes can. But it will take quite some time. Need to be patient. Best to direct feed. Since you only have drops, u can just massage and hand express every 1hour + direct feed. Pumps can be quite a hassle for now and might not be able to extract milk effectively. Once you have more milk then can start pumping. Try not to focus on collecting the breastmilk, focus on building supply instead. Its ok to just get few drops and wipe it off :) be consistent.

Any particular reason to want to restart pumping? Some are able to pick it up again by regularly pumping every 2h. But IMO, if baby is thriving with FM there should not be any pressure on your part to provide BM 😊 Fed is good

Best to consult a lactation consultant for this. Many factors to consider and they will be in the best position to advise on this.