You cannot apply for OPT unless you complete another program in the US.
Please note that this posting does not constitute legal advice or create any attorney-client relationship with the inquirer. Avvo is a useful forum to obtain general information on legal issues, but is not a substitute for direct, confidential consultation with an attorney in any legal matter.
OPT rules are rather strict about when you are eligible. You must sign up based on a degreed course of study either in your final year(s) of study toward the degree or within a fixed period of time after completing your degree. You have left the US which leaves you without any immigration "status" in the US. OPT is an extension of your F-1 student status which is now over. Unfortunately, you are out of luck. Sorry.