If you are using a super soil or a soil mix as you described, you shouldn't have to feed for at least the first 4-6 weeks. I'm guessing the feeding as some play in this, only feed when the plant looks like it needs fed, if it looks happy and healthy let it be.
I think your main problem is over watering. Firstly, you shouldn't be watering every day with a plant that young, with those temps, and with that size of pot. Second, do not water the plant when just the top is dry. A good rule of them is if the top 4-5 inches of soil is dry, you want to water. And easier method that I use is just lifting the pots.
Lift your pot after you water, feel how heavy it is. Then next time before you water, lift it. If it feels light, it needs watered, if it still feels heavy, let it go another day.