Oh hush Dranak...I'm not that bad
But no, I don't think you need to recast with a teenage character if you don't want to. If anything some teens have worse mouths on them than truckers.
Sex in novels depends on the characters and genre. Since yours is horror you can leave it out or put it in and it shouldn't be an issue.
Same with language. The only time you need to watch your cussing is if you are writing YA works. Otherwise, the best bet is to stay true to your characters. Let them say what they'd really say without censoring them or forcing them to cuss.
For instance in Apparitions you'll hardly ever see Bailey cuss and when she does it's the light version of it. Andy on the other hand can be quite blunt with his swearing.
If you're staying true to character in swearing and sex then you shouldn't have any issues (either way) in the adult market. Editors only get fussy with it when those things are tossed in as 'sides' or to make a puff book more interesting - which the technique fails on both accounts.