What everyone else has said about finding a PA job is extremely valid.

I worked at major studios while in college, and can tell you right now that it's going to be rough getting a film internship at somewhere big like HBO or Warner with the experience you have. You'll be up against other applicants that have experiences at both smaller production companies and name brand studios.

Now, that doesn't mean you shouldn't apply. And what I can say is that your U!Shine experience is really unique and you should definitely leverage that in a cover letter. I'd recommend applying to marketing/social media roles at these bigger studios since those aren't as competitive as the production/film related ones. It'll get you a good step in the door for the future if you want to go the studio route of eventually becoming a production coordinator. What they're looking for in a lot of these applications is project management skill and your U!Shine experience seems to fit that bill pretty well.

I'd also recommend looking at smaller production companies and unpaid internships (I know it sucks, but you have to slum it out and gain some experience). My professional experience started as a freshman in college with an unpaid internship doing marketing for film studios. To be blunt, it was terrible and the lack of pay didn't help. But it definitely helped me in gaining my next internships at name brand places. From there, I went into interning and working at a major studio.

I guess what I'm trying to get at is that you have to start somewhere and unpaid internships in the film industry (suck ass), but also give you the necessary experience to ramp up your career. If you look at Indeed, there are a decent amount of them for development, production, and post-production that you could definitely at least get an interview for. Best of luck man!