That's not how I and the founders saw individualism. Because individualism is inherently bound in responsibility. Responsibility to deal with the consequences of your decisions and the protection of your family/relations/whatever you connect with.
What you're calling individualism is actually hedonism and is actually no respecter of self. They are not remotely the same thing.
Hedonism however stems from individualism. Major problem with democracy and any similar system is that humans are naturally short-sighted, unless (and oftentimes even when) given a proper incentive. So if you teach people that individual is the only thing that matters, or even that individual matters far more than anything else, that will automatically lead to hedonism.
As for "the protection of your family/relations/whatever you connect with", that is actually not individualism, it is low-key collectivism. Which is why I said that a balance of individualism and collectivism is needed for a healthy society. For example, in a traditional society you do not need social security net or social care because extended family will take care of any individual that gets into trouble (sickness, old age and so on). This is in fact the system which Communists tried to emulate on a large scale (well, they did more than that...). Problem is, such a system does not work without an extended family, and you cannot emulate it through state institutions either. Reason why is psychology. In a traditional society, sure, if you cannot work, you will receive help. But a relatively high degree of collective dependence means that anyone who can work, but does not, is subject to social stigma and scorn - and these are extremely powerful motivators (in many cases, people will rather die than face social stigma). So what happens when you try to emulate such social safety net through formal institutions is that you leave out large parts of why it works: you have safety net, but because of individualism, people do not face stigma for exploiting it. And this leads to socialism where almost nobody works.
How is Croatia being destroyed today?
Basically? We have the downsides of Capitalism and Communism both, without having either of their upsides. Politicians and the other members of the ruling class consist of Communists - either old Communists from time of Yugoslavia or, increasingly, their biological and ideological descendents. So it is nearly impossible for fresh ranks and fresh ideas to come up. Bureocracy inherited from Communism means that it is difficult to start anything - it is much easier to simply connect yourself to the state and live at taxpayers' expense, you only need to join the Party - and the Communist mentality means that being a member of a political party is far more important for success in high positions that whether you can do the job. We have some private enterprise, but that too is in large part either aiming to connect to the state funding or else is run as a Communist-style dictatorship - meaning that actual private enterprise is much rarer in Croatia today than statistics would suggest. And even only statistics paint a very bad picture - public sector accounts for
full 45% of Croatia's Gross Domestic Product. Combine this with the previous, and less than half - much less than half - of GDP is genuine private sector. Communist mentality also means that public sector itself is run far worse than it could be - when they tried cutting personnel in the healthcare they gutted the people actually doing the work, while leaving worthless rubberstampers around, with the result that now we have a lack of former (e.g. doctors, nurses) and a
significant excess of the latter.
You have a lot of this with Progressives in the West - they are, after all, Communists. But Croatia never actually left Communism, so we have been suffering under it from 1945.