Falcio
I did exactly that. I did 13 years as a military assistant. Did my AFISO licence on leaving and spent 13 years ( my choice ) doing that leaving as a Senior Fiso and local examiner. Took a short backward step as a civil ATSA for about a year before starting an airport funded ADI licence in 1999 aged 42. 15 years later I have ADI, APP,APS,OJTI & UCE endorsements. The learning curve was very steep and difficult at times but doable if you REALLY want it.
Everyone is different and there is no reason why you won't be able to achieve your goals. It took me a long time to get there but I did it. Only you will know how much you really WANT it.