If you believe that other factors besides his work stress were the cause for the break up and he more interested in listening to his friends than someone who has feelings for him, then it is time to move on. You do not forget the past 3 years nor the times you've spent together.
From what you've shared, he is using work pressure as an excuse for the separation. If he is not able to be straight forward with you and tell you where he stands, it would be healthier to move on. Even if you try your best, XXXXX XXXXX has to let you know what is really going on, what he wants, and what he's willing to do to repair the relationship.