I'm very sorry to raise this, but when I see a post like this about a man suddenly claiming he doesn't love his wife any longer, is unhappy and has started a new job in recent times, my thoughts instantly turn to the possibility that he has met someone else at his new workplace.
In fact, I've never known this set of circumstances and there not to be another woman involved.
The very worst approach to this is to 'give it time' because even subconsciously, you will be trying to get him to love you again and if there is someone else involved, that will be a fruitless task because if it's an affair this isn't about you and you will be jumping through endless hoops to no avail. There is also no motivation to make a decision if an ambivalent person still has all his choices intact. Loss is the greatest motivator and antidote to ambivalence.
He might well be a 'good man' but good people have affairs.
The failsafe strategy in this situation is to take control and tell him that you cannot stay with someone who isn't sure of his feelings for you. As a pragmatist however I would also counsel you to be vigilant to any evidence of an association with someone else and to look for your own evidence of that rather than asking your husband about it. Logically, if there is someone else and he hasn't disclosed that already, he doesn't want you to find out about it. Given what you've said and my experience of seeing this very situation played out in RL and on MN many times over the years, I would be astonished if there wasn't someone else involved.
Discovery of this is devastating, but it does bring matters to a head and a couple can only make wise decisions about the future once all the information is known by both of them. It is far better to know than two possible other scenarios; you competing for his affections while staying together or him leaving at your request, keeping an affair secret and then wanting to come back when it's ended. Acknowledging that an affair is involved is painful and you might decide there's no way back from it, but at least that would be an informed decision and not one made blindly without knowledge. Conversely, many couples find that discovery stops an affair in its tracks and with effort, it's possible to build a new relationship as long as the other relationship is terminated immediately.
Please consider this carefully and forget any illusions you might have about your husband being a 'good man who isn't the type'. There are no types, but there are a lot of people in happy relationships who meet new colleagues and fail to put up any boundaries in a new friendship.