I think my husband and I need a seperation, where do I start?

My husband and I have been married for 5 years, he used to be a party boy, had lots of sex partners, done drugs, since our marraige hes been to rehab (he was a meth head) I recently found out hes been to Jail more times than he ever lead me to believe and he also has told me he thinks Im leaching off of him ( I work full time at a School) his behavior has changed back to his verbal abuse I just want a clean break I need advice HELP!