You will just have to keep on playing clean games. There's really not that much else to it.
It might take some time until you unlock your honor level but eventually you will be eligible to once again rise in Honor levels.
If you find yourself getting frustrated easily and voicing that via the in-game chat using the
/mute all command is definitely a good idea (all relevant communication can be done through pings).
Note that single reports won't really hurt your progress to getting your honor level unlocked again. Random players reporting people are unfortunately a thing but as long those reports remain an exception you shouldn't have any trouble.
Also: If you find yourself getting frustrated consider taking a break from the game for a moment to calm down. Everyone gets tilted from time to time but if you do realize it some distraction doesn't hurt.
Link to the Riot Games Honor FAQ:
PENALTIES AND LOCKS
How do I drop a level in Honor?
You’ll only drop if you receive a penalty. A chat restriction knocks
your Honor level to 1, or 0 if you’re already at level 1. A two week
suspension will drop your level to 0 (even if you were higher). In
both cases, your honor progress will be locked, making your account
ineligible for hextech crafting rewards. Your honor progress will
unlock some time after your restriction as long as you show signs of
What do you mean by lock my Honor level and rewards?
You'll see a lock on your Honor level in your profile. This means you
aren't making any progress to the next level, and you won't receive
any rewards. Unlock your Honor level by putting clean games in. You’ll
get a notification when you’ve unlocked your Honor level.
What's the deal with level 1 and 0?
If you fall below level 2, you were hit with a penalty or two, and the
first step is to put in clean games to unlock your Honor level. Once
you do, your games help you climb back to better rewards, just like
how it’s worked since Loot launched.