My boyfriend (28M) has not proposed to me(29F) yet, should I break up with him or wait it out?

My boyfriend (28M) has not proposed to me(29F) yet and I’m not sure if I should walk away or wait it out

My boyfriend (28M) and I (29F) have been together for almost four years and have been living together for a little over a year. Before we moved in together, very early on in our relationship, I was upfront about my personal stance—I don’t want to live with a partner for more than two years without being engaged. It’s something I feel strongly about based on what I’ve seen in other long-term relationships.

We have a very good relationship, and I have only one real complaint which is him having a pretty crazy ‘boy mom’. This doesn’t impact us a huge amount as she lives across the country and we seldom see her. Apart from that, I am very happy with him. We’ve had multiple conversations about marriage, the most recent being a few months ago. He shared some reservations, some of which made sense to me while others didn’t. While we discussed them at length, I’m still unsure about where he truly stands. I don’t want to continue living together and integrating our lives if marriage is off the table for him. I like to think if it was, he would tell me, but what if he doesn’t and just breaks it off at the end of the year when our lease is up?

Now that we’re approaching the two-year mark of living together, I’m feeling anxious that he won’t propose. I don’t want to find myself in a situation where I let this go on and then I’m waiting indefinitely, but I also don’t want to walk away prematurely if this is just a temporary hesitation on his part. Marriage is obviously a big decision that should be taken very seriously.

For those who have been in similar situations, how did you handle it? How can I approach this conversation again in a way that leads to clarity for both of us? Any insights would be greatly appreciated.

Edit: As stated above in my post we have talked about this several times. I am not avoiding any conversation or holding back. I have communicated with him my expectations several times, most recently 2 months ago. A lot of comments are asking what his reservations were. They are complicated and for personal reasons and privacy I won’t share but I will say they are reservations we are both actively working on together that can be overcome and are definitely not deal breakers which is why I am conflicted. I wonder our ability to smooth out these reservations by the end of the year and I’m concerned that my boundaries may be pushed because of this.

TL;DR: My boyfriend (28M) and I (29F) have lived together for nearly two years, and I’ve always been clear that I want to be engaged within that timeframe. He’s expressed reservations, and I’m unsure if a proposal is coming. How can I approach this situation effectively?