Expat relationship - future and settling down

I'm originally from Australia but have been living in the UK for the past three years. I've been in a relationship with my English boyfriend for about a year, and I'm very much in love with him. However, I'm starting to feel anxious about the future.

I've always envisioned moving back to Australia to be closer to my family, especially if I have children one day. I haven’t talked to him about this yet, and the thought of bringing it up makes me nervous. I don’t see myself living in the UK permanently, and I’m unsure how to approach this conversation without damaging our relationship.

Do you have any advice?