Wow OP you need new friends. These sound nothing like friends. They sound jealous. I'm bloody jealous - I used to travel the world and I can't now I have kids. Love my kids but they do restrict what you can do and are very, very expensive!
And why the hell do people think moving back in with parents is a failure? You've lived independently, it sounds like a success that your relationship is so great with your Mum that you'd rather live with her (and save money for travelling, buying a house or whatever) than pay through the nose (destroying your saving options for the future) for some no doubt much more crappy room in a shared house with strangers?
If you want to buy a house or do more extensive travelling, living with your Mum is a no brainer and I bet she loves having you around.
I have severe PCOS and I had a baby at 43, naturally (also had one in my late 30s naturally after spending my late 20s and early 30s trying unsuccessfully via IVF at great cost).
29 isn't a huge age for having children (I can't believe I'm writing this) but if having children is something that is one of the most important things for you, you could consider egg freezing, particularly if you don't want to have to compromise on who you have children with. Or you can choose to go it alone, but that is a big decision and commitment.
The only thing that I think has some merit in what these "friends" have said is that it's worth considering how big of a deal children is for you and there are things you can do (egg freezing) to give you options if you don't meet the right person to raise a family with until later.
However, I would say that I have friends who are childless not by choice (through infertility or not meeting the right person until their 40s) and who went through a period of really wanting children in their late 30s but now, in their 40s and 50s, are living exciting lives of travel and being hands on aunties to friends children. All the people I know in this position say they are glad life turned out the way it did for them.
I also have a friend who's always known she hasn't wanted children and all she's ever wanted to do is travel. So she works, saves (and this has included living with parents for various periods) and then goes on the most amazing month long trips around the world. I live vicariously through her facebook photos. She has a very full life.