Lots of stories use swearing, as long as it’s in suitable moderation it’s ok.
As for suicide, It’s ok as long as it features a trigger warning, as someone mentioned - a skip option is the best thing to do. Also, I came across this post where the poster made badges to put on covers for stories. In the link, there is a trigger warning badge you could feature on your covers.
My advice is to make it as clear as you can at the very beginning of episode 1 that the story contains a storyline featuring mental health and suicide. This gives anyone the opportunity to not read your story from the get go rather than reading halfway through to get to a point where they decide they can no longer continue to read. Sensitivity is the most important thing.