First of all, (hug).
I bet you aren't feeling very good right now. All that effort seemingly gone away for nothing, due to x y or z reasons. It isn't very fun and doesn't feel very fair. I would give you some chocolate to help you feel better were I beside you, but I am not, of which I apologize, and hope you find a source of chocolate soon.
Have you taken a visit to https://support.riotgames.com ? From here you'll be able to access the ticket system, where you will be able to submit a ticket regarding the crisis you are currently facing with the loss of your account! If you prefer, they are also available via the live chat feature, but that is available only during the day between certain hours (seems to start around 3pm central?). In doing this, you may be able to find out what has happened to make this ban happen. Sometimes bans are placed by mistake, and it only requires a little bit of investigation for Riot Support to help you determine if this is the case, and possibly get your account unbanned!
While you wait for a response, how about watching a movie? Something you haven't watched but have been meaning to, or something you've watched before but always makes you feel good! Or how about playing one of those games you've been meaning to get around to playing but haven't because League of Legends is so awesome? This is a perfect chance to do those things to help increase your happy!
Chances are, much of your playing has probably made you very stressful. Trying to get that kill but they get away with an inch of health, or your blue buff got stolen. Maybe someone afk'd 5 minutes into the game and you have to suffer through the rest of it, or maybe you're trying your best but players are putting you down left and right because you aren't playing perfectly. This may be a good time to sit and reflect on something very important: am I having fun? If you are playing league of legends and it is a joy every time you step into Summoners Rift or Aram, keep on playing to increase your joy! But, if you've gotten to a point where you step into a game thinking "I bet someone is going to afk, we needed a tank but they picked someone stupid, their matchup is wrong, they picked dumb summoners, I bet my support is an idiot, i'm tired of losing these games cuz of the people around me" you might be at a point where League of Legends is bringing you less happiness than you deserve. This may be your chance to take a break from something that is causing you more unhappy than you need in your life right now, and perhaps try newer and better things out there! This could even be the time to catch up on some book you've been meaning to read since forever, or a TV series you've been meaning to watch!
Don't take the banning as a personal attack against you, none of us dislike you and you are loved for who you are, try seeing it as a blessing! Just send your ticket to Riot Support and take a relaxing break. Bubble bath and chocolate! Maybe just lay out in the yard and watch the stars a bit. Breeze deeply and find your happy. :)