Whoo you lost the game. This will happen to you from time to time so please be nicer to your teammates. Let me point out some specifics.
Set the mood poorly by making a (to be fair minor) racist comment. First impressions are everything and this predisposes them to not like you:
Lucian..
GIMME KFC
Things seem to be proceeding ok, you're keeping it light, and theeeeen:
plz dont feed my lane
i can tell ur new
Looks like a poor gank happened. Everyone on your team realizes that a mistake was just made. In this case it's better to say something encouraging or at the very least nothing. Criticism no matter how well deserved helps nobody. Especially when they are well aware they made a mistake. It's also worth mentioning you were matched with that player which means your relative skill levels aren't that far apart. They probably have as much experience as you do. Hence it's an unfair and unwarranted statement.
Then we see a good sign
blitz plz dont take cs im not trying to be mean plz
You're a little frustrated but still have good intentions and are trying to hold it together.
Oh baby, it breaks
WHAT KIND OF GANK WAS THAT?
IM GOING TOP
IDGAF
Due to a game going poorly and some mistakes you go all caps and yell at your teammates. You are now officially toxic, congrats! Not only did you yell at your teammates you're now proposing a trolly move.
Gonna skip the criticism of blitz's q skills...
report blitz unskileld boli feeding they ruined this game
Actually they played poorly this game and contributed heavily (?I didn't see the game) to your loss. You're ruining the game by making your teammates feel sad/angry/shamed. Everyone loses in this game. People play poorly. Mistakes are made. It sucks, but you have to think less about winning and more about doing the best that you can with what you're given. even losing you can still have fun and get experience. If everyone is being friendly and encouraging each other things improve drastically. (on a side not, unskilled reports are basically a placebo. Riot doesn't actually do anything with them because it's silly to give punishment for not being as good as your teammates think you should be)
This next part is just denial, and right after a particularly insulting line
dont play at all if u use game modes as an exuce for being bad LMFAO
im not toxic
You are calling everyone on your team bad and telling them to never play the game again. At which point you laugh at them. That's really quite toxic and just ruins people's day.
I'll skip over the rest of the game, needless to say you're not being horrible, but your comments are just a bit rude and demeaning. After the game
im quitting this gane for a week
maybe ill stay in a hospital
cuz my teamates gave me cancer
...Wut. Seriously. Maybe you were just trying to be funny? But it's not really amusing. Either a nice person just feels really bad about themselves, or most feel really pissed at you.
Ok that's my breakdown of this game and why it can be considered toxic and reportable. I really hope that you don't take this as me trying to bash on you. I wouldn't have taken the time to read through and analyze everything if I was. I just wanted to point out the areas that you seem unable to see and hope that you will take this ban to heart. You are talking to people here who at best will just shrug it off as silly and worst will be hurt. Consider your words carefully and if you have nothing nice to say (that will happen) just don't say anything at all.
TLDR: (Please read what I wrote, it won't take too long) Yes you were toxic in this game and likely others. Please take this time to think about the way that you treat others. Building them up works sooo much better than tearing them down. Your teammates will do a lot better if you're encouraging them. If you don't it's likely this won't be your last ban.