To give you the honest answer, no, you probably wouldn't be able to post that. You've said it already - Tapastic is a webcomic website. That's the only straightforward answer you need and you already know that.
Have you ever tried places like WattPad or FictionPress.net? (the latter being the original works sister site of FanFiction.Net lol). They're built for written works like your own, unlike Tapastic.
If I can be even more honest here, and frankly, a little bit harsh to kick you into shape lol if you really, really want to do it as a comic, and you have the skills, what's stopping you? Having other commitments like college is just, dare I say it, an excuse. There are people on here who are in school, working part-time/full-time jobs, and still find the time to make their comics because they care that much about the project they're doing. My own series, Time Gate: Reaper, is a 10 year project so far, and I probably won't be finished drawing it for the next 20+ years (and since I started it, I've been updating it every day, despite college and my job as a barista at Starbucks). Is it daunting? Yes. Is it intimidating? Of course. But I have a story I want to tell using the skills that I have, and by god I'm going to do it, and I think you can too 
Instead of looking in the future, focus on the now. Maybe do one page a week to start. It doesn't have to be full color either - black and white or greyscale is also an option. There's no rush to jump into the ocean of webcomics right away, especially if you have other commitments at the moment. Set a schedule that works for you, and just go for it. It's one thing to not be able to do a comic because you lack the artistic skills, but if you already have some former training and know what you're doing, the only thing that's stopping you is yourself. And then when you're finished college, or are able to free up time, or maybe even some day, get to the point that you can make a living off your stuff, then you can consider changing the update schedules to twice a week, or three times a week, or every day, whatever floats your boat and doesn't run you ragged.
If you don't decide to do it in comic form on Tapastic, then that's your decision. You pick what works for you and you only. If you choose to do it as a novel, then do check out places like WattPad, do some "internet-browsing" of other writing-based websites. If you do it in novel form, those places will undoubtedly offer you better tools and a better experience than Tapastic will, as a website that's made for comics.
I hope that was able to motivate you in one way or another, haha. Whatever you choose to do, good luck!
