Are you doing your part to make it any better though? You yourself said you "shitpost", so wouldn't you be contributing to the problem if that is truly the case?
Here is a scenario. On /vr/, another blue board (blue boards are safe for work boards, still 18+ of course) about gaming to those not versed in this sort of thing, there are lots of great hardware threads. Because things are so on-topic, you see less shit, but if you do, the janitors seem to be fairly quick to take care of things. I bring this up because sometimes in CRT threads, racist content and off topic convos do get posted, but people report it and it gets taken care of.
Remember, racism and trolling is not allowed outside of /b/. If you see something out of guidelines, report it. You can always hide offending posts too, or use an extension as a more comprehensive blocker.
Basically...
1.
If it isn't making you happy to visit and post there, stop posting. I know you say you are hooked, but sometimes we have to make a deep effort to stop and take a look back and admit that if something is making us miserable, we owe it to ourselves to stop. Install a content blocker for it or any other websites you care not to see.
2. If you are going to post, don't shitpost and actually contribute to a thread or topic.
Don't add to the problem, instead do something constructive for the thread you are in, as you would in any other community.
3. If you see shitposting, derailing, racism, trolling, illegal content, etc, just report it (
just as you would report something innapropriate on Era).
4. If you do plan on staying,
Stay on the blue boards. I myself have only been on blue boards and am happy that they got segregated as 4channel, away from 4chan.
5.
Realize that like reddit, 4chan is at the end of a day an image-based discussion platform with hundreds of sub communities. Maybe get off /v/ and talk about some toons on /co/, or post your laptop stickers on /g/ or find your next favorite wallpaper on /w/. There's gonna be shit, but a lot of good stuff too. There's good and bad people everywhere, so the important thing to remember is that wherever you go, since you are the only one you can control, always be a good person.
Just some thoughts on the matter. Regardless of what you decide, I wish you nothing but the best. Remember that if it isn't brining you joy, you don't have to go there, you can quit. It may be hard, but it could be worth it.
I used 4chan from ages 13-17.
You shouldn't have been on it at all at that age. It's an 18+ community.