I love web-designing, and for a large majority of my life, it has remained a strong hobby of mine, but let me tell you, there are WAY more jobs in graphic design, than for Architecture.
Marketing is a very competitive field, on par with architecture, because you can't just "decide" to be good at it. You have to fail during some campaigns, which can be a deal-breaker for some people, as it a very risky career.
I would recommend that you do a major in computer science or software engineering if you like the coding aspect, graphic design/communications if you like the design aspect, and if you just like working with the internet, then an Information Technology (IT) major.
A lot of web designers end up broke. You should pursue something more secure, like the majors above, and use web design as a possible part-time job during your student years. Decide why you like web design, and use the statement to discover what alternatives you can do.