This is hard to accept, but please don't think he may change his mind, he is being clear, very clear.
One of my best friends married, wanted children, and her DH put off the discussion for 8 years until she was well into her forties...her chances have gone, she is heartbroken.
The desire for children overpowers everything, even love for a partner for many....
Think about the life you want 5,10, 15, 20 years from today, what do you want in it....
I did this when l was unsure about having children and found l couldn't bear the thought of my life without children, it became clear.
I am so grateful, as l changed my direction in life hugely to make sure l had dcs.
No one can tell you what is right for you but you need to think carefully about the future, will he be enough, and will you regret it if you break up.