So you want to get faster, but you've been lifting 2x a week and sprinting 1x a week? What are you doing the other days? What has your lifting been like and how have you progressed?
It's a little late to change your plan now, but why don't you post what you've done and we can see what may be causing this. Adding strength alone will not get you faster if it adds on extra lbs, decreases your mobility or flexibility, or takes away from high quality sprinting.