Well for one thing, in order to have strong finger nails you are doing it all wrong, I am sorry to say.
You need to EAT the nail strengthener and PAINT ON the jello.
Secondly, a finger nail is only as strong as the finger it is attached to. You need to get a finger-workout tape and have your fingers do a regular workout to it. Preferably one with jazzy music so your fingers don't get bored.
Thirdly, you should pay more attention to your finger nails. You know they say plants that you talk to do better than those you don't, so talk to your finger nails. Tell them how pretty they are. Take them out to a movie or dancing. Make them feel 'special'.
Be good to your finger nails and they will be good to you.