Hi OP, I haven't RTFT but in your shoes, I'd leave.
The thing is that if you twisted his arm, he would most likely resent you.
I love my kids and I wanted them both but they are the hardest thing I've ever done. Unless you have millions and can use night nannies, it's YEARS of broken sleep and being needed all the time, and feeling burnt out and exhausted.
When things are shit, the easiest person to blame for your unhappiness is your partner - that's why divorces are so common.
You both have to 100% want it, or it's a veto.
He doesn't have all the power though - you can choose - do I want to have kids more than I want this relationship? If yes, then leave. If no - then take reasonable steps - get your fertility checked and maybe freeze some eggs or whatever your doctor advises - and stay in it, and value the relationship.
Don't let him decide for you though. One of my closest school friends dated a "not sure yet" guy for almost 10 years, 31-41. They were TTC when he was finally "ready" when she was 38, but it never happened. At 41, after the last round of IVF failed, he left her, saying the process had broken him. 6 months later he shacked up with a younger woman and now has 2 kids with her. It's taken years for my friend's MH to recover.
He has time to waste, but you don't. Make your choice, take control, take responsibility. However it shakes out you'll feel better if you take charge of your life, and don't wait around for him to decide for you. Best of luck 