Not sure if HR is the best choice of confidant...
At least here in the US, where there are very few worker protections, HR is not tasked with making sure you're happy. Their primary goal outside of basic payroll/benefits functions is to reduce the company's liability caused by their employees. I'd liken it to having to call the police to resolve a problem -- once the police are involved, the situation is typically so bad that you can't recover from it easily. Police are just going to sort it out the best they can, and someone will (figuratively) "go to jail" to resolve it. I've never had anyone I know who went to HR for a problem not regret it later. This is especailly true for some friends I've known in long-service government jobs where they're basically stuck with the same manager they've had a dispute with for their entire tenure.
I'd say the best choice, if you can manage to do so, is to find a new workplace. That's not an easy thing always -- I have a family and am not about to move across the country for a job that may or may not be stable, for example. When you stay somewhere you're miserable, everyone has to deal with it.
There's no doubt that stress in IT is real, and it takes many forms. Some workplaces are constantly in layoff mode and threatening the staff with that blunt weapon. Some work you to death. Some are just so backwards and clueless that it drives the clueful crazy. My personal way of dealing with it has been to continuously remind myself that it's only a job. You'd be surprised how many people forget that and let it eat them up inside!