@k290, if I recall correctly, you're in South Africa and have been investing. I don't know any numbers for your income and savings, other than some inflation rates and such from investing threads, so will address this question from the relationship aspect primarily.
You mention social anxiety. Like others, I suspect that at 29, if she wants to spend time with you, and you don't want to be near her roomies to see her, yes an apartment with room for a nice bed is a good idea for the relationship. Would you still have a positive savings rate after getting the apartment?
"Save" the relationship implies to me that:
1) you two have a relationship
2) it's in trouble
3) the apartment will save it.
If all of these are true, and you have a positive savings rate, then your new apartment path is a normal adult thing in the society I know (USA). Can't speak to South Africa knowledgeably.
In other posts, you referred to your current dwelling as "a shitty apartment." If you can afford better, and honestly feel it's shitty, move...but what is afford? Uncertainty about whether you'd be saving 90% or 10% or nothing in the new-apartment situation is much more important that the ratio of apartment rents.
So are the feelings of the lady in question, and also the godparents. What have these parties said about the situation exactly?