You don't have to re-do your ghusl for sexual discharge unless you have both ejcaulation and semen discharge at the same time. See hadith below:
I used to get emotional urethral discharge frequently. Being the son-in-law of the Prophet (ﷺ) I requested a man to ask him about it. So the man asked the Prophet (ﷺ) about it. The Prophet (ﷺ) replied,...
و عليكم السلام ورحمة الله وبركاته
There are duas for waswas during wudhu and Ghusl in
While you're on the shower, spit three times over your left shoulder to get rid of waswas. If yiu keep ignoring them, inshalla they'll go away.
Regarding your second question xthat should be fine. ...
I don't think this invalidates ghusl. There are distinct things that invalidate ghusl and you can google those. I think other punitive things such as the one you mentioned is totally fine. Remember, Islam is religion of peace, and simplicity. We always complicate matters, but always remind yourself this. :)