Lozar, I think you're hung up on sexuality a bit, and your analysis is insufficiently nuanced. It isn't as simple as "too much sex = bad," as we have to say why exactly sexualization is a problem, and in what contexts. Incidentally I think greater sexualization and sexual liberation is ceteris paribus a good thing, but that specific phenomena, such as the sexualization of children (which you bring up) are problematic. On the topic of the sexualization of children, I think capitalism is to blame. If sexuality can be sold as a commodity (whether an abstract "commodity" or a physical item), and we live in a commodity economy where everyone has to participate, as many fundamental social relations take the form of relations between commodities produced by human labor, put two and two together and the sexualization of children is an unfortunate but predictable outcome.
Anyways, I think a lot of our problems are the products of capitalism insofar as 1. it creates externalities and 2. commodity fetishism (the above phenomenon I described where complex social relations become indirect via commodities sold on a market) forces an "everyone for themselves" mentality to develop, which creates massive social coordination problems. Some of the worst things we are confronting, like climate change, global water shortage, etc., are actually both market externalities and social coordination problems. Broadly speaking, I think we need to create a society where the working class (defined as people who do not own society's means of production, i.e. those who have nothing to sell but their own labor, which they must sell to survive in the market economy) seizes control of the global means of production ("means of production" broadly defined, including factories, energy infrastructure, natural resources, etc).