Last minute Shot Glass DIY project. HELP?

My roommates birthday is coming up. One of the gifts I am giving her is a DIY Shot Glass. I am writting her name in white puffy paint, letting it dry, then covering the entire glass in white fabric paint (the only paint I have). After that dries, I plan on adding glitter to the bottom section of the shot glass using modge podge and putting some fine gold glitter over that. I have nothing to use as a "sealer" so I was thinking the closest i can come is clear nailpolish.

My Questions are:

I have heard that when painting glassware, it is a great idea to put it in the oven to set it. If I were to do this, at what stage would it be best to put it in the oven? (Pre glitter, post glitter, post clear nail polish?)

Is there anything I can use in place of an acrylic sealer to make the glass shine again/keep the glitter into place?

Do you have any other suggestions to better this project? Please keep in mind I am a college student, so I don't have many materials available to me(no craft store near by)

Thank you so much, I would appreciate ANY tips i can get... I really want to make this special and don't want to screw up!