This is where things get a bit tricky. Again, as of this writing, there are tons of reports of Instagram being down for people across the country, but when the application is running smoothly on the backend, it has a few safeguards in place in order to combat bots and spam accounts from populating the platform.
The first reason you might be receiving the "We limit how often" and "Try again later" messages could be because you're using third-party add-on apps with Instagram that violate the end-user agreement. Your account might be banned as a result, but these bans usually only last anywhere from 24 to 48 hours.
If you want to continue using Instagram, then it's probably in your best interest not to use these third-party resources. While some of them may be perfectly innocuous, others are used to mass-follow accounts in the hopes of gaining more followers. Then, after two months or so, the apps automatically unfollow those accounts and hope to retain a percentage to boost the number of people who see their content.
Instagram has been pretty good at putting the kibosh on these kinds of applications, but even if you aren't using these kinds of pieces of tech, you might still receive error messages.
If you're the world's fastest commenter, for example, Instagram may try to slow your roll and stop you from spamming content on its platform.
You may also notice that this error typically occurs after you update your Instagram application. So if you notice that happens a lot, that's the the culprit right there.