As long as you didn't give up on Satan and Zevism by mentally acknowledging you don't want to be a Zevist anymore, then everything can be corrected.
We learn from past mistakes, we correct them and we grow. Satan knows we are human beings, therefore we are not yet perfect. Everyone makes mistakes, dedicated or not, the dedication does not mean we become automatically perfect, but means we get on a path of betterment, and Father and the Gods are very patient with us.
If you feel needed, talk directly to Gods, Satan and/or your Guardian Daemon (if you don't know who your GD is, just refer to Him/Her as Guardian until you find out), and tell Them how you feel about the past, what you've learned and your hopes for the future, letting them know you're sorry. If you've made huge mistakes, something really bad, and you feel is needed, you can do this in a standard ritual.
But if what you've done is not that serious, then the above is not the case. Keep meditating, keep advancing, because as you said, you have learned your lesson, and I see you're in a process of changing for the better.
HAIL ZEUS!