DE,
I fully understand your situation and desire to improve, but know that until you get around players of a certain level and do effective training, you will improve only slowly with many dysfunctional stroke and play habits.
I was a recreational player for several years in a very similar situation to yours. I was in the military and everywhere I was at, the closest TT club was 2-4 hours drive away, simply too far to go more than once a moon. So like you, I had no coach, no way to know how I was bad, where I was bad, how to correct or anyone to hit and help me get some of that ironed out.
I did what I could by my self. I read Larry Hodges Steps to Success Table Tennis, I joined every major TT forum, I went to tourneys where I could. I practiced serves... but all that is gunna do is keep a player at the 1000-1600 USATT recreational player level.
All that changed when I got assigned to Korea and had a TT club 5 minute walk from where I lived.
Still, you have a chance to enjoy table tennis and still improve some, that counts for a lot. Some places you go, there is zero TT.