My(M29)fiance is ready for the next steps in our relationship but I(F23)am not ready

Me (f23) and my fiance (m29) have been together for 4 years.

When we met he asked me when/if I would want children and I told him that I do not want to have children until I am at least 25, married and own a home or at least have stable housing (we live/lived in an area with a rental crisis). At the time he agreed with this and validated my choice.

But over the last year or so he has started making comments like "I don't want to have kids when I'm too old to jump on a trampoline with them" and other comments saying that he wants kids soon and doesn't want to be an "old dad". Today is my fiances 29th birthday and a few days ago we had a big fight that resulted in me saying that we might be incompatible and that he should end the relationship if he isn't happy. He is not happy because I am only working part time right now and want to study to get my high school diploma(I did not finish high school)and further education. Whereas he wants me to go back to work full time and put off study so that we can pay off our 30k in debt and then save a deposit for a house. We have shared finances and he has also been contributing significantly more to our finances than I have over the last 2 years.

I understand why he feels the way he does but I feel like putting off study any longer would be a huge mistake in my life. I love him and do want to have a family with him in the future but I think that he wants this all much earlier than I will be able to provide/agree to. Our relationship has also not been very healthy in the past and my trust in him is broken so I currently feel a little worried about making big commitments like marriage/house/kids.

My feelings are really conflicted and I don't know how to talk to him about this. How do I compromise and find a solution in this situation/communicate all of this to him?