No contact and no response to my texts?

I met a really great guy almost 3 years ago and we were a really great match. He was and is still a great guy. However, I broke up with him and tried to work things out with an ex. In March we began talking again and have since then. I've had a difficult because with his job he is out of town all the time. We both live in Austin and he's working in Houston. We've only been able to see one another 4 or 5 times since March. He has made it very clear that with this current project he's not even supposed to have his cell phone in the building. Needless to say, he rarely responds to my texts or will say "boss here." About a week and half ago he was asking I truly loved him and I said yes. He asked what I would say if he asked me to go to Vegas and marry him. I said in time I would as soon as my kids understood that this was going to work and how much we love one another. I said in a year or so and he said "Well, start getting those things in order and be prepared." We went on and on and then of course he went back to work Monday before last (9 days ago) and the convos started getting shorter. Well, now I haven't heard anything from him since last Wednesday. I sent a couple texts and haven't attempted to try again since Friday or Saturday with NO response. I just don't understand how he's discussing marriage and then blow me off. He's not the type to have someone else and/or play games. He's a NO DRAMA guy. He is going to be 40 in a week and has never been married, has no kids and has never lived with anyone. Is he trying to tell me something or is it just that he's not used to having to "check in" so to speak? I just feel like giving up on a great guy but don't want it to be a misunderstanding. PLEASE HELP???!!!