It's not unusual for a new grower to overdo everything. I've been there, myself. Time and experience are the best teachers. Fortunately marijuana is a very resilient plant when it's allowed to do it's thing.
Almost always, new growers will overwater the seedings -thinking that the more water they provide, the more they will drink it up. New growers often over fertilize young plants, too. They often don't have a good light. They don't provide good air movement or have a source of fresh air. They don't have any experience recognizing pests or deficiencies so they often treat the wrong pathogen -again with too many items, all at once, to try and get an overnight response. When we, as humans, drink too much, we can recover in a matter of hours...But, as has been mentioned, plants may take weeks to recover. They work on a different timeframe. As a new grower, waiting can be the hardest part.
Continue to do lots of reading and watch a lot of videos and begin to dial in your grow room environment. Plan on having some plants die along the way. It's part of the process and everyone has a "war story" to tell if they've been growing for awhile. Good luck!