Author title for ex-student in research paper
For a definitive answer: check issues of the journal you will submit to, see what they do. If you still have doubts: contact the editor (I would wait until after acceptance of the paper, because it's not such a big deal).

My take on it:


First, it's very rare to mention the diplomas hold by the authors. Even the titles (Dr, Prof, etc.) are often not listed at all. The exceptions seem to be (at least in my field) some journals edited by German societies, academies or publishers (Angewandte Chemie lists all titles, for example, in a footnote along with full affiliations). So, I'd remove the “MS in XYZ”.
Secondly, your main affiliation is the institution where you carried out your work (or most of it). This means, list “University of Nowhere, Department of Procrastination” as your main affiliation.
Thirdly, you can indicate your “current address” in the author list. Depending on journal style, it might be a footnote or listed as other affiliations. It will start with: “Current address: University of Big Name, Department of Corrections”. But… given that you don't have a new institutional address, I would advise you to skip it altogether. Simply don't list your home address in the paper, it's not really useful for readers. If they want to contact you, they will use email anyway.
Finally: if your former university didn't provide an email address that will last, using your gmail address is perfectly fine.


I hope this covers it!