I'm only 6 years in the Navy so, congrats. I'm not sure I'll make it to 20 myself. I have great respect for those who can. Some jobs are worse than others, but it seems to me almost all the jobs in the military are pretty high stress.
So, you're working as a contractor now? Going to get two retirements? Then you'll really be set. Have a great uncle that did that. Retired at 58 with a full pension (two half ones)