Game getting too boring, not fun anymore

I log into League of Legends after a long day of school, excited to waste my life away at my favorite game. I go into Teambuilder and browse through my rather small list of champions, wondering who to play. I find myself staring for 5 minutes before saying "God damn. These champs got so boring. I dont want to play any of them anymore. What happened to the joy this game always brought to me?" I play a game of ARAM to let the game decide who I play. I then get stuck with Skarner. "No way in hell I'm playing this thing." I dodge the queue and wait out the time penalty. I then join another queue and get Sivir. "Meh. Much better, still not very good though." I decide to play as Sivir. I got very fed, and karthus was doing really well. The rest of my team did extremely bad, and we ended up losing. I then realize I haven't won a single game of ARAM on this account, out of like 20. I go back to Team Builder. After a long thought process I decide to go akali mid. I lane against syndra and get my ass handed to me. We ended up losing that game. "Why can I not win anymore?" I go and play a game of Ranked. I go Kennen top against Jax. I won lane, but our Annie was lagging and ended up feeding enemy kat pretty badly. We ended up losing that game. "Why can I not win any ranked games?" I finally resort to blind pick. I called top and picked Cho'Gath. AP Cho sounded kinda fun to play. Another person on my team says "i'm top you fag" and locks in poppy. Me and my team argued with him, but he wouldn't budge. I did the right thing and went support. We lost lane, and then, of course, the game. "This is getting very tiring." I look through my list of champions again. "Why do I not want to play anything? Why is nothing fun anymore? I used to have a blast playing this game. I would play every game, win or lose, go through the whole thing, and enjoy myself afterwards because having fun is more important than winning. Now I dont have any motivation at all to play this game. Nothing sounds fun. Nothing sounds enjoyable. I cant even win a game anymore."

What has happened? This game used to be so much fun early in the year, now I can't stand playing it. Why has it come to this? Why is this game not enjoyable anymore?