> Feel free to critize, but I don't see evidence strong enough to immediately reject my theory with such a certainity. Of course not every long covid patient has IKEA furniture.

Can you please explain how this isn't evidence strong enough to immediately reject your "all long COVID is caused by IKEA furniture" theory?

> But IKEA is/was aware […] they actively hide facts […]

This is classic conspiratorial reasoning. You observe that group A do activity B to cover up activity C, which – if activity C causes situation D – would help cover up situation D. You then treat this as evidence that activity C causes situation D, and/or that group A is complicit in knowingly causing situation D; but this doesn't follow, no matter how much it feels like it does.

This kind of conspiratorial reasoning is extremely seductive – as I know from experience. I was never able to reason myself out of belief systems shaped like this. I'm hoping that laying this out abstractly will help bypass this – that you can look at the shape of the argument, go "yeah, that shape of argument is exceedingly questionable", then let that cognitive dissonance sit in your mind and gradually break apart the conspiratorial thinking over time – but I'm not really expecting it to help you.

I got lucky, because my conspiratorial beliefs (about big tech being evil cyberstalkers who collect and sell everyone's personal information) were never validated by others, and I began to doubt them (despite the mounting evidence), until I started to consider non-conspiratorial alternative explanations. It turns out, those have a lot more evidence to support them (as I'm sure most of HN is aware). This eventually allowed me to construct general models of the world where the "bad guys" are not necessarily omniscient, and these have served me well across a wide variety of topics.

> PS: There are some books/podcasts by doctors who themselves got long covid and felt the gaslighting by their peers and reported about it.

Please stay away from these. They are not healthy to someone with your mindset. You already know that the medical establishment is sceptical of the existence of ME/CFS, and only grudgingly acknowledges Long COVID: you don't need to expose yourself to repeated testimony from people with grudges and a vested interest in holding your interest.