Providing a possibly unpopular opinion:
I was in the same situation. Partner didn't want to commit due to being in a financially instable situation back then (him, not me).
Eventually, we decided to start trying for children. A year later, without any luck, he proposed, and 6 weeks later, we found out I was pregnant. Our relationship is now better than it's ever been, and we look forward to the arrival of our little one.
Before he proposed, I was in the same spot as you. I thought he just didn't want to build a family and future with me and he was also (as he'll admit himself now) really terrible at communicating his worries. He got a lot of "I don't know", "not the right time", etc from him when actually, he was very aware that I had a great job with good maternity leave package, he lived in my flat and so on. He knew from his mates that babies and engagement rings cost money and, for him, it was always about not wanting me to settle for anything less than what he thought I deserved.
When I thought he was making excuses because I had said I didn't need an expensive ring, etc, he wasn't going to propose with anything less than what he thought I'd really love.
Your opinions on these things will differ. Neither of you may currently be communicating what is really on your mind. That's okay. You just have to work out for yourself if you want this man in your life and if you're a good team. Don't let your age frazzle you either - you have plenty of time, so don't let society wind you up. It's not you against him. It's both of you together on your journey to discovering whether you'll be a family one day.
Don't forget, his role in all of this is not just to propose and agree to having a baby. It will be to look after you when pregnancy isn't much fun, to get up at night when the newborn won't sleep, to comfort you when a scan didn't tell you what you had hoped for.
Working in a minimum wage job can have a really negative impact on people's motivation levels and mental health. He might just not feel equipped for big life changes right now.