I'd take a look to see if you're qualified to have the Post 9/11 GI bill if they separate you. If you are eligible I'd think really hard about going to school and getting your degree now.
It doesn't get easier to go back to school, trust me. You always think you'll have time later, but you never do... until you make time. Do that now!
If college isn't your thing right now you'd probably be able to pass the POSS and/or MOSS testing to try to get into OPS at a civilian plant. You'd just have to take some practice tests to get used to the way the questions are presented. The problem there is that you're going to be competing against people who have real world experience in applied engineering, and you're going to have none.
Not to say that it can't be done, we have some very young NLOs at my plant who didn't have much experience coming in the door. They're way outnumbered by the NLOs who have a college degree or several years of Navy and civilian power plant experience though (some have all of the things I just listed).
Definitely take a look at the Federal jobs stuff... I believe TVA also gives some credit for military service so take a look there too.
Good luck!