Not only do you need to be speaking to someone, but your son does as well. He may be depressed and needs some assistance in that area. He shuts down because he may feel like you are grilling him about what he's doing, etc. No more questions about plans w/his father, etc. I know that many people shut down when asked about finding a job. Your son may feel like everything his hopeless and he needs counseling to help him. Sitting in a room all day, playing computer games, is an excape for him from the real world. He's depressed about a lot of things.
Yep, it takes about 2-5 years for the cooling off period after a divorce....I read that somewhere when I was going through the divorce. My attorney said give it two years and he would be contacting me. He was pretty much on target w/the timeline. The walk away has to go through the extreme euphoria of freedom in order to realize that you and the relationship weren't the problem. Now, whether or not they reconcile totally, that depends upon the couples and the situations. I certainly wouldn't sit around and wait on your xh. Eight months isn't a long time at all in the timelines that most of us have dealt with...you are still a "youngin" in the scheme of things. That's why it's important not to count the days, weeks, months...it makes it seem forever in a day.
Yes, I understand very much so about the calls at work and him making them quick. Mine use to do that as well....it's their way of contacting us and they know that we cannot keep them on the phone or discuss personal issues w/them while we are at work. BTW, no more driving by his place....you are stalking when you do this!
Make today the first day of a new chapter...do something different, even if it's cooking your son his favorite meal...it's time to turn the page in your book and start looking forward.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.