Do you know how many people still don't really use their PC, and therefore get all their web/communication needs fulfilled by their smartphone. Many of them won't keep buying PCs. Well, laptops. PCs are already out.
Do you like the arts? I find it completely uninteresting.
Why, particularly, does your girlfriend have to understand the beauty of Computer Science? Just keep making cool, useful, possibly world changing shit, and I'm sure she'll see the beauty there!
Start your own company immediately. You can give your day job higher priority, but definitely try your hand at this life! In 3 years when you graduate you will be thankful for the experience, or for the extra money you'll have in your pocket.
I have a THEORY that it is easier to get an internship at a Startup than at a large company (during your first 2 years of college). If you are willing to work for a little less (maybe free-- get equity, choose wisely), then you could snag an internship right after your freshman year, when normally your options would be slim (larger companies tend to have these rules that bar interns until their Junior year). Here's the good: while most are working at McDonald's during their first college summer, or sitting around, you will be gaining solid experience.
If you can't get a good enough internship, then remember to start your own company! This is especially true if you won't necessarily need to make money during the summer months. You can probably pilot and test your idea during the school year, and you can play a different story when its time to get your first full-time job. The experience of having your own thing on the side while in college will set you down a different path once you graduate. Also, it will help you select and see the benefit of taking a few business-related electives! This is important! You will learn that it is important to be able to manage finances (take a finance course!) as well as market your brand/idea/self (take a marketing/sales/branding course).
Starting your own thing on the side is likely to provide you with a context for the best possible real world experience you can hope for. After working on your own thing, and seeing what its really like out there, then you will have questions, and you will assess everything with a keen observational eye (when you go for your next internship). You may also be better equipped (awareness) to negotiate when its time to secure your first full-time job. You will also not need to ask yourself, "startup vs. large company vs. entrepreneur," as you will have tested the waters young.
The main benefit of interning at a large company is to see what its like at a large company.
If the money isn't a lot more, or the project isn't AMAZING, or you don't really need Google on your resume (at this stage of life), then don't bother.
Google is a great place to work in general, but you may be surprised at what you end up working on when you get there (nothing much).
If you aren't that happy with your current job, then give Google a go!