If you have less than a 1-year experience and no obligation on your credit report your personal income must cover the $500 dollar mortgage payment for DTI purposes.So, depending on your unique situation there's 3 outcomes DTI wise. 

I'm conflicted on the best way to approach my first deal funding wise.

Be very conservative with how much you can get rent wise. 

In light of that, is it still wise for me to buy US real estate?

A wise attorney will advise her to stop.

I think it was a wise decision. 

Is this being wise or just talking myself out of a goal because of fear?

@Scott Mac, thanks for the suggestion that was a wise idea.

A wise hard money lender would want some sort of assurance in advance.If you have enough equity in the property, perhaps you could refinance now and use that cash for the ADU?

Become financially literate making wise financial decisions on a daily basis and then learning everything you can about the world of real estate!