You walked away and you wanted him to follow you? That sounds like you’re testing him, seeing if he’ll jump through the hoops you set (but don’t clearly tell him about) to prove he cares.
Why else do you think he doesn’t care about you now when he did before?
Is it sudden, or were there things happening before the wedding and you pushed them under the carpet, perhaps, hoping that it was just pre-wedding stress and things would be better when it was over? Have you been particularly stressed and, perhaps, not as reasonable as you normally are because of the wedding? Are there things about the wedding/wedding planning that didn’t go the way you want? That have made you a bit resentful?
Weddings are stressful, so if it’s just a bit of a post-wedding crash, approaching it in a calm way, not engaging in drama about trivial things, having some compassion for his stress and your own, etc. is the way to go. Talk about issues if they come up, but don’t push things. And plan some easy things you both like doing together (like binging a TV show together or getting a takeout you both love, regular things you used to do - not some big event or anything expensive or high pressured) to help get into a non-wedding routine you’ll both be happy with. Give it some time. Then when things have settled, go to marriage counseling and develop better communication skills between you so that future stressful events don’t go the same way.
But if it isn’t just down to wedding stress, if this is really something that’s been growing for ages but the wedding has masked, or a new thing you didn’t see before that won’t get better, get out now. It may be hard. Mortgages and kids are not trivial issues. But it will be better than letting things fester for ages and then doing it in a few years (or, worse yet, not at all and just living with misery).