The one thing I wouldn't do is have this baby in Mexico. You have said yourself you are financially unstable there, difficulty affording rent and basic furniture, boyfriend not keen on a baby, your family aren't around. Also after the child is born your boyfriend may be able to stop you taking the child abroad if you later wanted to move back to Australia. I wouldn't want to raise a child in those circumstances.
People saying babies don't cost much money are missing that the major costs are lost earnings (and childcare when you do work), and extra housing costs (even when baby small and in your bedroom you may not be happy in your current area or apartment with a baby and want to move somewhere nicer). And of course babies grow into children who do cost more money!
Abortion- morally and emotionally I personally see no difference in a termination at 12 or 15 weeks. Obviously practically it's a different procedure, and everyone feels differently about abortion and it may feel morally or emotionally different to you, it's how you feel about abortion that's important, not how other people feel.
If you have a termination now but think you'd like to have a child in the future, I'd start taking steps to get into a position where you'd be better placed to raise a child. At 32 you do have time to get into a better financial position, new relationship maybe, decide whether to stay in Mexico or move, and get pregnant again.... but not loads of time.
If you choose a different avenue in life and prefer to travel and have adventures and pursue creativity over having a child thst is absolutely fine, lots of women make thst choice and are very happy and fulfilled. but I'd want to intentionally choose that rather than just not getting around to having a child then maybe regretting it.
If you want to continue this pregnancy I would move back to Australia, if your family will support you. Having a first baby is a huge change and I think you'll want secure housing, more financial security, family support and good medical care (physical and mental health).
I wouldn't want to risk getting stuck in Mexico if your boyfriend opposes you moving his child abroad. Even if he wants you to terminate now, he may still oppose you taking his child away once born. I wouldn't normally support intentionally moving away from the father, but bringing a baby into your current precarious finances, home and situation sounds like it will be very difficult.
If you do want to have a termination though that is absolutely fine, and don't let anyone make you feel bad if that's your decision.