Wow, there are so many nasty comments in response to your post. Heaven forbid something in someone's life doesn't go according to plan eh! Sometimes things happen in a different order than we'd imagined.
My husband proposed after 7 years. The difference was that getting married wasn't really important to me. We were happy living together (we bought our first home together). He was very much what people nowadays would call a "green flag" guy. I knew 100% he'd always have my back, that he adored me and I adored him, and that was enough for me. I'd spent time with a few horrors before meeting him, so I knew.
But marriage sounds like a deal-breaker for you, and that's completely valid. People value different things. Maybe commitment in the form of marriage is something he's been anxious about, but after 7 years I'd expect him to have thought about seriously.
What is he like as a partner and as a dad? Are you happy with him generally? Do you feel supported, loved and valued? Does he adore you and your daughter? Or is he a bit of a man-child in other areas of your relationship too? No relationship is perfectly equal, and I do beleive that women often end up doing a bit more of the day-to-day, but it shouldn't feel significantly one-sided.
He has maybe gone to his mum's because he needed some space to think after your conversation as you were very clear where you stand. None of us really know what's going through his mind.
Hopefully he'll come back wanting to talk properly. He may realise he does want to get married but he's been scared of taking that step. He may decide he loves you but genuinely doesn't want marriage for whatever reason. Or he may decide the relationship has run its course as he cant commit to marriage. As hurtful as that would be, at least you'd finally have clarity.
I really hope things work out the way you want them to. But if they don't, at least you can be happier in knowing you didn't just carry on wishing for something that mattered so much to you. You deserve to be with someone whose vision for the future matches yours, and your daughter deserves to see a relationship where both people want the same things. Whatever happens, you've been brave enough to ask for what you need, and there's nothing wrong with that.