What are the steps to a new life?

Like I have posted in any venue that i have access to, i have become quite stagnant. I do not feel that i am moving forward in my life. 30 kinda scares me. what did i think i would be doing when i turned 30? where would i be in life? did i even think about it until recently?
i like to say that i peaked in life early-maybe late high school/early college. is that just an excuse to not move forward? i'm constantly living in the past or in the future. where is my present? i don't want to look back & think that i wasted the best years of my life.
i'm not really trying even though i tell myself i am. i'm not putting the work in since i have always thought it should come naturally.
i do love my job & it does challenge me, sometimes too much. i need to get out of my head a little more & be more about action. my thoughts drive me slightly batty.
maybe a solid plan? how to i guarantee that i will follow thru? i go back & forth between being strong-willed & weak-willed. weird huh??!!