You dont have to sound like a jerk. I don't really try to pretend to be interested. I AM interested in things he does. I admit I do get bored but I like to spend time with him.
I never take him shopping, I wouldn't want him to shop unless it was for something he wanted anyway.
Sorry if I sounded like a jerk, but you needed a quick primer on how relationships REALLY work and your post showed your immaturity. I understand that you are relatively new at it, and I made some of the same stupid mistakes at your age (well, guy mistakes at any rate).
Spend time with him on things the TWO of you enjoy. If you spend time with him on things you don't enjoy and bore you, he WILL resent you for it. Count on it! He wants to enjoy his football. Having someone around who is bored and isn't enjoying what he is enjoying is a downer and will make you look clingy. Try the PS or Wii that you mentioned. Maybe if you learned to play football on the PS, you might garner more interest in the actual thing (who knows? and if you don't, no big deal). If the games he likes don't interest you, look for games that might interest you. The fact that you are looking for something the TWO of you can enjoy within his realm, ought to flatter him.
Lastly, the fact that he was depressed over the loss is a GOOD thing. It shows that he is capable of healthy emotional attachments. A lot of younger guys aren't emotionally mature enough for anything more than superficial emotional ties at that age. Haven't you ever had an emotional reaction to a movie or a book? Then imagine that it isn't just a book, but a series of them you've been reading for months or years and you can't wait for the next one. Then when you finally reach the climax of the series, the protagonist dies. Most women I know would have a profound emotional reaction to that. This is the same to him. He has, at least, one season, maybe an entire life's worth, of emotional attachement to HIS team. Yes, to you, it is just a stupid game, but to him, it is much, much more.
The fact the he expressed a mature emotion like depression is great (as opposed to something like anger and even violence, which is not uncommon amongst college aged (or sadly even older) males after the "big game" that ends in a loss, hence why riots tend to erupt after such games).
You may not understand this, but as the woman in the relationship it is your job to help nurture that emotional growth and help turn him into an emotionally healthy man (a process that takes years btw). For his sake, don't ever belittle his emotions like you did in the first post, even if it was relatively minor thing. And yes, I know that isn't what you intended.