Soil is do-able its just your crazy watering techniques droughting the plant.
Have you got more seeds?
This time i want you to soak the entire volume of the soil (i use three inch pots but solo cups are about the same size just cut the top centimeter off and remember to cut drainage holes).
When the soil still looks wet/damp but the pot feels lighter by quite a bit BINGO water the whole lot again.
Fuck that spray bottle off 100%, maybe your gran or mom might find a use for it somewhere - we use wet dry cycles and water again when a certain percentage is lost... easy dude.