DT, this is the same old problem I've pointed out before with the way you treat sources. You pick out snippets from various sources and then stitch them together in an an interpretation that is not consistent with the entire collection of data. Do South and Lei say that the metoo movement intimidating young men is a significant factor in the overall reduction of sexual activity in young people? No!
Of the possible explanations considered, the decline in the formation of romantic relationships and decreasing alcohol consumption are the most important, but declining earnings and increasing use of computer games also play important roles. Overall, the measured explanations explain three-quarters of the decline in young adult sexual activity. Within individuals, forming a romantic relationship, going to college, and alcohol consumption likely have causal effects on the probability of engaging in sexual intercourse.
On average, young people in committed relationships have more frequent sex than those who don't. So, if young people are putting off committed relationships longer (which is consistent with other indications of a prolonged adolescence in young people), that would fully explain why the demographic you are interested in, men in their 20s having sex with women in their late teens, would see a substantial decrease in the frequency of having sense.
They did a follow up study on young adult casual sex and found that 75% of the decrease in men is explained by decreased alcohol consumption, living with parents for a longer period of time, and playing video games. The single most explanatory variable for women was decreased alcohol consumption. You've been preaching on the evils of alcohol consumption lately, so you're kind of hoist by your own petard on that one.
As for the difference in numbers from the Pew Report that you keep insisting has only one explanation, one of your own sources disagrees with you. Jon Birger attributes that difference to voluntary choices by men to postpone committed dating relationships. As the percentage of women in colleges has increased, it has become less important to "lock in" a female partner by investing the time and effort in a committed relationship. With women making up the majority of students, men can have sex without the investment of time and effort in a committed relationship. At least that's what he says in his published books and articles.
According to the Pew Report, both sexes report the difficulty in approaching each other as a factor that discourages them from dating. But that's far from the only factor that is reported as discouraging them from dating. For young men especially, too busy with work is a important reasons.
I don't have the time or the interest to chase down all of cherry picked snippets out of which you have constructed your Gish Gallop. But I can see you doing exactly doing the same thing we've talked about before: cherry picking from studies out of confirmation bias instead of reading the literature and trying to arrive at some reasonable conclusions about what is going on.
Nothing in your many snippets provides any sort of explanation for why IHAQ's comment made you feel anxious. I'd suggest that anxiety is best addressed with a good therapist as opposed to pouring over scientific articles looking for nuggets to confirm your biases.