I fear rejection is never easy and you just have to develop a thick skin with these things. Getting 3 things rejected from the BBC is no big thing (they've rejected tonnes of my stuff over the years) and the odds of getting on shows like Newsjack and TSWYW are just a few %. (If it was pure random luck...)
Stick that Kipling poem up on your wall to remind you not to get too weighed down by failure and try writing for lots of different things. The odds are more in your favour for things like Kirrin Island, Treason and Newsrevue and Kirrin Island does give you feedback on your writing (*)
Sometimes it's just a matter of taste and style, stuff that one person rejects another will love. This is will become apparent if you ever send sketches to both Treason & Newsrevue.
So keep going and try writing for lots of different things and different people to see how you get on.
[And don't worry about the prostitutes thing - on here we have incredibly thin skins when people might be slagging us off and we try to use humour to deflect that]
(*) Need to declare an interest - I'm a script editor on Kirrin Island hence plugging it.