First, a request to all questioners. Try not to text speak too much, even if you are asking a question from your phone. I only have to edit your question!
I can see two possibilities:
1/ He is getting ready to roam, or already is.
or, far more likely,
2/ You have been together long enough that you have become a habit to him. You know, boring. Long enough varies from guy to guy – for some it is a couple of years, for others a couple of decades, but it always happens unless you guard against it.
You know the phrase “the grass is always greener?” That is where he is at right now. A little innocent text flirtation, to liven up a life he is finding dull.
He doesn’t really see you any more as a person with needs and feelings. That hurts a lot. You get resentful, rightfully, and he picks up on that and his interest drops even more.
Thats is not to say he doesn’t love you, just that he doesn’t really notice you unless he is forced to.
Now, the answer to your third question depends on which case it is.
If it is the first possibility, you had best get angry, sharpish. Yeah, you run a risk of losing him physically, of course. But you have already lost him emotionally. May as well fight to get him back.
If it is the second one, spice things up. Force him to notice you again, in as many positive ways as you can. A week or so ago I got asked why mysterious men were apealling. The exact same thing applies to women.
I’ll not lie, it’ll feel like you are trying to push a bus uphill at first. But it does work. If it is worth doing it? Well, that is up to you.