[enfilade]

Former Marine infantry corporal here -- I think lbo's advice to you is outstanding. He/she wrote:

"Anyway, don't defeat yourself and don't underestimate how critical this knowledge will be in 10, 15, 25 years when the world will be a whole new place filled with much much more software."

Maintaining a long term perspective is key. The skills you are seeking will only rise in value in the coming years as computing becomes more and more ubiquitous and distributed. Maintain the mindset you have at the beginning of a 20k hike with crew-serve weapons and full packs.

You are 25, technically oriented/interested, and you're a former grunt NCO. As long as you stay healthy and avoid stepping in front of a bus you will be working for decades to come. You may feel old, but in the big scheme of things you are not.

I understand your problem is short term money. Have you considered working for a year with DynCorp or Xe as a security contractor? You could have 125,000 after a year and could keep coding when you're inside the wire. With that financial cushion things could be smoother.