simultaneously want to know everything there is to know about Romans, but also want something else to learn in college.

If you keep this mindset, you'll get burnt out. Knowing things is great; it is also inherently unsustainable and bounded. Coming from another archaeology and Classics major, the real excitement is discovery.

When you're high school, you learn how to learn. The biggest difference between a freshman history class and and upper-level, advanced history class is not the "difficulty" of the information. It's the amount and the expectations of what you do with it. Entry-level textbooks are necessary because they present information in straight-forward, easily comprehensible chunks. They're heavily subdivided into paragraphs and sections with visible headers, there's graphic organizers galore, and primary sources have annotations out the wazoo. Beginners need instruction to know what to get out of texts and how to do it- you can't just give them a book and say "Learn!" As a senior with well-defined interests, you've gone beyond all that. You can read and comprehend the information available in most any text.

When you're in college, you learn how to discover and create. Professors can throw loads of readings and lectures at you because they no longer need to teach you how to take it in. Classes in your major will teach you how to do research and how to critically examine material and information you find: "Here's what we know, go and find out more!" For archaeology this will extend into lab methods, field methods, and classes on specific places or topics. You'll also want to go to a field school, where you'll work at an actual excavation. If you go the classics route, you'll start with intensive language classes (if you haven't already done Latin or Greek) and, depending on your interests, move onto intensive readings of Classical literature or seminars on history/art history/etc. You can, of course, do both. In either case, the curriculum is not about how much knowledge you get out of it. There is a certain base-level of expertise you'll need to acquire, but if you approach college expecting just to learn "things," you will quickly burn out. You should look forward to building the skills that help you contribute to existing knowledge.

With these skills, you can approach the real driving motivation of academia: questions. Everyone one of us here has a regional or temporal specialty, and we probably chose that because we think it's interesting. Yet what keeps me alive at 2 AM on my 12th cup of coffee, knee deep in incomprehensible GPR survey data, are those research questions that push you ever forward: how do people incorporate the past into their contemporary traditions? How are structures of authority enforced and reproduced through architecture, and how do people respond? Even, small, innocuous questions like "Why does this figure on the sculpture get a hat?" It's a historians or archaeologists jobs to pursue these questions to the limits of our knowledge, and to keep going just a little bit further.

Early in your career, it's easy to get caught with taking in everything that we do know- there is so much. Ultimately, history and archaeology are about inquiry, asking questions to build on or fill in gaps in existing knowledge. If you're scared to oversaturate yourself, remember that that's not what college is about. (And trust me, until you've read tomes on Roman tax law, there's always more to learn about Rome.) Read to your heart's content, but, more importantly, ask questions. Does an author drop a juicy anecdote about a 2nd-century general that leaves you with a "Huh?" or a "Why?" Follow that thread- what source does that author cite? Who does that author cite, or is it a primary source? What is the nature of the primary source? Can we trust it? Has anyone written any books or articles about the author? No? Well, you've got yourself a paper topic right there! In college and grad school, you're going from the consumption of knowledge to the production of knowledge, and that's a task that will never be finished.

(Also keep in mind that it's totally cool to have historical interests that you don't pursue academically. My shelf has books on cubist poetry, big band leaders, and multiple histories of National Parks- I'd never claim to have approached these topics as a scholar, but enjoy them nonetheless)

You'll never get burnt out if Roman history is something you truly want to study. If I had to make a suggestion, though, it would be to find some aspect of Roman history that you find endlessly fascinating. For instance, perhaps the Julio-Claudians would bore the hell out of you, but the Severans might not. You may find you're more interested in say, Roman epigraphy or numismatics than what you think you would be now. Heck, it may not be Roman history at all that you ultimately fall into. You have plenty of time.

TL;DR: Don't sweat it, and let your interest evolve organically.