I don't think you're being selfish at all! I did the same thing and joined the Air Guard when I was 25 (Now 28) with a wife, son, and one on the way. I was and still am employed at a regional and got hired on to fly C-130's which I'm doing training for right now before I head back to my unit. UPT was long but I was able to have the whole family head down with me and my wife was able to get a leave of absence from work for a year and taught off base.
The whole thing has been a great experience! Aside from being able to serve our country, it's given us different perspectives on lots of subjects and has opened tons of opportunities. I'm definitely planning on staying in as long as they'll keep me.
Let me know what other questions you've got!