question

Damping off. To high humidity/moisture. A few ways to prevent this are to When watering young plants don't let the soil where the stem comes out get wet. Water 1-2" around the stem. have the soil by the stem slightly higher so water washes away. Sprinkle cinnamon around where the stem comes out as it is a natural fungicide. at this stage I would say you have a 99% chance she will die. I have salvaged a damped off plant but I have lost more. If it is an auto flower then don't bother. What I did is bury the damping off section with dry soil. I would go to the top of your toothpicks. You can use duct tape and paper to make your pot larger for the time being. Transplanting would be death. Now the infection is under the soil. Take 5ml of 3% hydrogen peroxide. Dilute it with 5ml of water and slowly add that to the base of the stem trying to have it all soak down and not run off.( I use a syringe with blunt tip needle ) With the amount of water you have already you should not have to water for 1-2 weeks. Little plants don't drink much and you want to get a good dry spell. Good luck

RIP 😥

She's damping off... and the only way to solve that is to prevent it so there's nothing that you can do here, unfortunately... You've kept your medium MUCH too wet so next time, keep the soil MOIST, not WET... best way to do that is to use a spray bottle to water the soil around the seedlings and make sure the soil is dry before giving another dose. Sorry, mate!