I have a feeling that your intentions are sincere, so let me try to help.
Your comment was probably not downvoted because of your views, but because you said "Stop lying", which violates this community's standard of civility. It also makes you sound boorish, which hurts your argument. I appreciated the informative part of your comment, but your tone unfortunately canceled it out.
(Your other comment, complaining about downvoting, violates the HN guidelines even worse. Please don't ever do that. It makes you look bad and is rude to everyone reading.)
On controversial topics, including Iran, HN has its share of zealots. One need not look far for an example: responding to a claim that Iran has started no wars by redefining "war" to mean "unsavory domestic policy" is mind-bogglingly contemptuous of fact. But there are also many fair-minded people who are not so excitable and denunciatory. Here is how to reach them: (1) supply good information; (2) stop. (2) is harder than it sounds.
Keep in mind that most Westerners have no way of distinguishing propaganda from fact in the many things they hear about Iran. That's not because they're bad or dumb, it's because they haven't specifically looked into it. But most don't want to, which means there are limits to how convincing you can expect to be even in your best-case scenario. The only way to optimize that is to be scrupulously polite.