The is a sign that our friendship is drifting apart.?

My best friend and I have been friends for a long time (little more than twelve years) and recently, I've been noticing that we're drifting apart. FYI, our friendship is very competitive even though we don't show it on the outside or ever talk about it. We always try to one up one another. Sometimes he would one up me and I would one up him so that neither of us ever really out does one another. Sure we've had numerous fights throughout our history both verbal and physical but they weren't anything that couldn't be repaired. We both recently graduated from college and for a little while, we were both looking at a very uncertain future both because of the economy and the usefulness of our degrees (me in psychology and he in history). All was good because we seemed like we were in the same boat but that wasn't the case for too long. Right before graduation, I took the initiative to rethink my life and decided to chase my dream (architecture) so I thought, what the heck and applied for grad school in architecture (very good ones because I thought why not?!). Everyone had their doubts and weren't holding their breathes because how can someone with a psychology degree ever get accepted into architecture school without prior experience? Well, after I graduated, I spent almost every waking hour learning the CAD programs and completed a portfolio and submitted my application to grad schools. Recently, I found out that I got into grad school. Everyone was surprised, including my parents. Of course when I found out, I told my best friend. Although we celebrated, I began to notice that things between us seemed a little off. A couple of days later, I noticed that we had very little to say to each other when we hung out but of course I shrugged it off because I thought it was just a temporary dose of envy on his part. Eventually, I stopped talking about grad schools and didn't tell him about other schools that I also started hearing back from because I didn't want to rub it in his face. For a little while, it seemed to help but something was still a little off. Last night, when we had beers with some of our other friends, we all got a little buzzed and got into a debate about random things that were not even in the ball park of architecture. However, all of a sudden, he made a vile remark about my future field of study. Of course, I shrugged it off but after we all went our separate ways, I began to think about his remark and it dawned upon me that we've reached the point of no return. Although it wasn't anything that cut to the core, what he said was just an indicator to the fact that enough in-congruence has built up to the point that our friendship can never return to the way it was. Sure we'll hang out but I won't confide or have the same trust in him like I did in the past. Have you ever experienced this and would you agree that I'm not over reacting?